diff --git a/Makefile.inc.in b/Makefile.inc.in
index d1e1da4..699ac77 100644
--- a/Makefile.inc.in
+++ b/Makefile.inc.in
@@ -99,7 +99,7 @@ LIBS_LIBPULSE      = @LIBPULSE_LIBS@
 LIBS_LUA           = $(TOP)vendor/luajit/src/libluajit.a
 LIBS_OPENAL        = @OPENAL_LIBS@
 LIBS_PORTAUDIO     = @PORTAUDIO_LIBS@
-LIBS_PTHREAD       = @PTHREAD_LIBS@
+LIBS_PTHREAD       = @PTHREAD_LIBS@ -lpthread
 
 ifeq (yes, $(BUILD_DARWIN))
 LIBS_LUA           = $(TOP)vendor/luajit/src/libluajit-aegisub.so
diff --git a/libaegisub/Makefile b/libaegisub/Makefile
index 4efb685..f53c372 100644
--- a/libaegisub/Makefile
+++ b/libaegisub/Makefile
@@ -44,7 +44,8 @@ aegisub_OBJ += $(d)common/dispatch.o
 endif
 
 aegisub_PCH := $(d)lagi_pre.h
-aegisub_CPPFLAGS := -I$(d)include -I$(TOP) $(CPPFLAGS_BOOST) $(CFLAGS_LUA)
+aegisub_CPPFLAGS := -I$(d)include -I$(TOP) \
+	$(CFLAGS_PTHREAD) $(CPPFLAGS_BOOST) $(CFLAGS_LUA)
 
 $(d)common/charset_conv.o_FLAGS := $(CFLAGS_ICONV)
 $(d)common/parser.o_FLAGS := -ftemplate-depth=256