diff --git a/Makefile.common b/Makefile.common
index b02681564a..5a6ecc78b4 100644
--- a/Makefile.common
+++ b/Makefile.common
@@ -45,7 +45,8 @@ else
 
     INCLUDE_FLAGS += \
     	-I$(SERENITY_BASE_DIR)/Libraries/LibC \
-    	-I$(SERENITY_BASE_DIR)/Libraries/LibM
+    	-I$(SERENITY_BASE_DIR)/Libraries/LibM \
+    	-I$(SERENITY_BASE_DIR)/Libraries/LibPthread
 
     LDFLAGS += \
         -L$(SERENITY_BASE_DIR)/Libraries/LibC