diff --git a/Libraries/LibC/stdio.cpp b/Libraries/LibC/stdio.cpp
index 99d6f15a1a..1cdf9d4a73 100644
--- a/Libraries/LibC/stdio.cpp
+++ b/Libraries/LibC/stdio.cpp
@@ -953,8 +953,8 @@ int snprintf(char* buffer, size_t size, const char* fmt, ...)
 void perror(const char* s)
 {
     int saved_errno = errno;
-    dbg() << "perror(): " << s << ": " << strerror(saved_errno);
-    fprintf(stderr, "%s: %s\n", s, strerror(saved_errno));
+    dbgln("perror(): {}: {}", s, strerror(saved_errno));
+    warnln("{}: {}", s, strerror(saved_errno));
 }
 
 static int parse_mode(const char* mode)
@@ -987,7 +987,7 @@ static int parse_mode(const char* mode)
             // Ok...
             break;
         default:
-            dbg() << "Potentially unsupported fopen mode _" << mode << "_ (because of '" << *ptr << "')";
+            dbgln("Potentially unsupported fopen mode _{}_ (because of '{}')", mode, *ptr);
         }
     }
 
diff --git a/Libraries/LibC/unistd.cpp b/Libraries/LibC/unistd.cpp
index de5838be4a..b35f011289 100644
--- a/Libraries/LibC/unistd.cpp
+++ b/Libraries/LibC/unistd.cpp
@@ -133,7 +133,7 @@ int execvpe(const char* filename, char* const argv[], char* const envp[])
         int rc = execve(candidate.characters(), argv, envp);
         if (rc < 0 && errno != ENOENT) {
             errno_rollback.set_override_rollback_value(errno);
-            dbg() << "execvpe() failed on attempt (" << candidate << ") with " << strerror(errno);
+            dbgln("execvpe() failed on attempt ({}) with {}", candidate, strerror(errno));
             return rc;
         }
     }
@@ -146,7 +146,7 @@ int execvp(const char* filename, char* const argv[])
 {
     int rc = execvpe(filename, argv, environ);
     int saved_errno = errno;
-    dbg() << "execvp() about to return " << rc << " with errno=" << saved_errno;
+    dbgln("execvp() about to return {} with errno={}", rc, saved_errno);
     errno = saved_errno;
     return rc;
 }
@@ -708,7 +708,7 @@ ssize_t pread(int fd, void* buf, size_t count, off_t offset)
 
 char* getpass(const char* prompt)
 {
-    dbg() << "FIXME: getpass(\"" << prompt << "\")";
+    dbgln("FIXME: getpass('{}')", prompt);
     ASSERT_NOT_REACHED();
 }
 
diff --git a/Libraries/LibCore/Gzip.cpp b/Libraries/LibCore/Gzip.cpp
index 268e9a4702..49cf14c3a0 100644
--- a/Libraries/LibCore/Gzip.cpp
+++ b/Libraries/LibCore/Gzip.cpp
@@ -50,7 +50,6 @@ static Optional<ByteBuffer> get_gzip_payload(const ByteBuffer& data)
             ASSERT_NOT_REACHED();
             return (u8)0;
         }
-        // dbg() << "read_byte: " << String::format("%x", data[current]);
         return data[current++];
     };
 
@@ -67,7 +66,7 @@ static Optional<ByteBuffer> get_gzip_payload(const ByteBuffer& data)
     // Compression method
     auto method = read_byte();
     if (method != 8) {
-        dbg() << "get_gzip_payload: Wrong compression method = " << method;
+        dbgln("get_gzip_payload: Wrong compression method={}", method);
         return Optional<ByteBuffer>();
     }
 
@@ -79,7 +78,7 @@ static Optional<ByteBuffer> get_gzip_payload(const ByteBuffer& data)
     // FEXTRA
     if (flags & 4) {
         u16 length = read_byte() & read_byte() << 8;
-        dbg() << "get_gzip_payload: Header has FEXTRA flag set. Length = " << length;
+        dbgln("get_gzip_payload: Header has FEXTRA flag set. length={}", length);
         current += length;
     }
 
@@ -155,7 +154,7 @@ Optional<ByteBuffer> Gzip::decompress(const ByteBuffer& data)
 #endif
             destination.grow(destination.size() * 2);
         } else {
-            dbg() << "Gzip::decompress: Error. puff() returned: " << puff_ret;
+            dbgln("Gzip::decompress: Error. puff() returned: {}", puff_ret);
             ASSERT_NOT_REACHED();
         }
     }
diff --git a/Libraries/LibCore/Socket.cpp b/Libraries/LibCore/Socket.cpp
index 98d8b2566a..4ced6734b1 100644
--- a/Libraries/LibCore/Socket.cpp
+++ b/Libraries/LibCore/Socket.cpp
@@ -75,7 +75,7 @@ bool Socket::connect(const String& hostname, int port)
 {
     auto* hostent = gethostbyname(hostname.characters());
     if (!hostent) {
-        dbg() << "Socket::connect: Unable to resolve '" << hostname << "'";
+        dbgln("Socket::connect: Unable to resolve '{}'", hostname);
         return false;
     }
 
diff --git a/Libraries/LibCore/UDPServer.cpp b/Libraries/LibCore/UDPServer.cpp
index b7aaea78e7..6716865e6b 100644
--- a/Libraries/LibCore/UDPServer.cpp
+++ b/Libraries/LibCore/UDPServer.cpp
@@ -86,7 +86,7 @@ ByteBuffer UDPServer::receive(size_t size, sockaddr_in& in)
     socklen_t in_len = sizeof(in);
     ssize_t rlen = ::recvfrom(m_fd, buf.data(), size, 0, (sockaddr*)&in, &in_len);
     if (rlen < 0) {
-        dbg() << "recvfrom: " << strerror(errno);
+        dbgln("recvfrom: {}", strerror(errno));
         return {};
     }
 
diff --git a/Libraries/LibCpp/Lexer.cpp b/Libraries/LibCpp/Lexer.cpp
index 0153c21760..831822e5a5 100644
--- a/Libraries/LibCpp/Lexer.cpp
+++ b/Libraries/LibCpp/Lexer.cpp
@@ -780,7 +780,7 @@ Vector<Token> Lexer::lex()
                 commit_token(Token::Type::Identifier);
             continue;
         }
-        dbg() << "Unimplemented token character: " << ch;
+        dbgln("Unimplemented token character: {}", ch);
         emit_token(Token::Type::Unknown);
     }
     return tokens;
diff --git a/Libraries/LibCrypto/ASN1/DER.h b/Libraries/LibCrypto/ASN1/DER.h
index 9f78efba97..0c4c63e2f1 100644
--- a/Libraries/LibCrypto/ASN1/DER.h
+++ b/Libraries/LibCrypto/ASN1/DER.h
@@ -35,14 +35,14 @@ namespace Crypto {
 static bool der_decode_integer(const u8* in, size_t length, UnsignedBigInteger& number)
 {
     if (length < 3) {
-        dbg() << "invalid header size";
+        dbgln("invalid header size");
         return false;
     }
 
     size_t x { 0 };
     // must start with 0x02
     if ((in[x++] & 0x1f) != 0x02) {
-        dbg() << "not an integer " << in[x - 1] << " (" << in[x] << " follows)";
+        dbgln("not an integer {} ({} follows)", in[x - 1], in[x]);
         return false;
     }
 
@@ -51,7 +51,7 @@ static bool der_decode_integer(const u8* in, size_t length, UnsignedBigInteger&
     if ((x & 0x80) == 0) {
         // overflow
         if (x + z > length) {
-            dbg() << "would overflow " << z + x << " > " << length;
+            dbgln("would overflow {} > {}", z + x, length);
             return false;
         }
 
@@ -63,7 +63,7 @@ static bool der_decode_integer(const u8* in, size_t length, UnsignedBigInteger&
 
         // overflow
         if ((x + z) > length || z > 4 || z == 0) {
-            dbg() << "would overflow " << z + x << " > " << length;
+            dbgln("would overflow {} > {}", z + x, length);
             return false;
         }
 
@@ -74,7 +74,7 @@ static bool der_decode_integer(const u8* in, size_t length, UnsignedBigInteger&
 
         // overflow
         if (x + y > length) {
-            dbg() << "would overflow " << y + x << " > " << length;
+            dbgln("would overflow {} > {}", y + x, length);
             return false;
         }
 
@@ -84,7 +84,7 @@ static bool der_decode_integer(const u8* in, size_t length, UnsignedBigInteger&
 
     // see if it's negative
     if (in[x] & 0x80) {
-        dbg() << "negative bigint unsupported in der_decode_integer";
+        dbgln("negative bigint unsupported in der_decode_integer");
         return false;
     }
 
@@ -243,7 +243,7 @@ constexpr static bool der_length_sequence(ASN1::List* list, size_t in_length, si
             y += x;
             break;
         default:
-            dbg() << "Unhandled Kind " << ASN1::kind_name(type);
+            dbgln("Unhandled Kind {}", ASN1::kind_name(type));
             ASSERT_NOT_REACHED();
             break;
         }
@@ -258,7 +258,7 @@ constexpr static bool der_length_sequence(ASN1::List* list, size_t in_length, si
     } else if (y < 16777216ul) {
         y += 5;
     } else {
-        dbg() << "invalid length " << y;
+        dbgln("invalid length {}", y);
         return false;
     }
     *out_length = y;
@@ -268,12 +268,12 @@ constexpr static bool der_length_sequence(ASN1::List* list, size_t in_length, si
 static inline bool der_decode_sequence(const u8* in, size_t in_length, ASN1::List* list, size_t out_length, bool ordered = true)
 {
     if (in_length < 2) {
-        dbg() << "header too small";
+        dbgln("header too small");
         return false; // invalid header
     }
     size_t x { 0 };
     if (in[x++] != 0x30) {
-        dbg() << "not a sequence: " << in[x - 1];
+        dbgln("not a sequence: {}", in[x - 1]);
         return false; // not a sequence
     }
     size_t block_size { 0 };
@@ -282,14 +282,14 @@ static inline bool der_decode_sequence(const u8* in, size_t in_length, ASN1::Lis
         block_size = in[x++];
     } else if (in[x] & 0x80) {
         if ((in[x] < 0x81) || (in[x] > 0x83)) {
-            dbg() << "invalid length element " << in[x];
+            dbgln("invalid length element {}", in[x]);
             return false;
         }
 
         y = in[x++] & 0x7f;
 
         if (x + y > in_length) {
-            dbg() << "would overflow " << x + y << " -> " << in_length;
+            dbgln("would overflow {} > {}", x + y, in_length);
             return false; // overflow
         }
         block_size = 0;
@@ -299,7 +299,7 @@ static inline bool der_decode_sequence(const u8* in, size_t in_length, ASN1::Lis
 
     // overflow
     if (x + block_size > in_length) {
-        dbg() << "would overflow " << x + block_size << " -> " << in_length;
+        dbgln("would overflow {} > {}", x + block_size, in_length);
         return false;
     }
 
@@ -343,7 +343,7 @@ static inline bool der_decode_sequence(const u8* in, size_t in_length, ASN1::Lis
             break;
         case ASN1::Kind::Sequence:
             if ((in[x] & 0x3f) != 0x30) {
-                dbg() << "Not a sequence: " << (in[x] & 0x3f);
+                dbgln("Not a sequence: {}", (in[x] & 0x3f));
                 return false;
             }
             z = in_length;
@@ -357,7 +357,7 @@ static inline bool der_decode_sequence(const u8* in, size_t in_length, ASN1::Lis
             }
             break;
         default:
-            dbg() << "Unhandled ASN1 kind " << ASN1::kind_name(kind);
+            dbgln("Unhandled ASN1 kind {}", ASN1::kind_name(kind));
             ASSERT_NOT_REACHED();
             break;
         }
@@ -369,7 +369,7 @@ static inline bool der_decode_sequence(const u8* in, size_t in_length, ASN1::Lis
     }
     for (size_t i = 0; i < out_length; ++i)
         if (!list[i].used) {
-            dbg() << "index " << i << " was not read";
+            dbgln("index {} was not read", i);
             return false;
         }