diff --git a/extensions/sdktools/Makefile b/extensions/sdktools/Makefile
index 5244968f..160dc702 100644
--- a/extensions/sdktools/Makefile
+++ b/extensions/sdktools/Makefile
@@ -12,7 +12,7 @@ SOURCEMM = ../../../../sourcemm
 PROJECT = sdktools
 
 #Uncomment for SourceMM-enabled extensions
-LINK_HL2 = $(HL2LIB)/tier1_i486.a vstdlib_i486.so tier0_i486.so 
+LINK_HL2 = $(HL2LIB)/tier1_i486.a $(HL2LIB)/mathlib_i486.a vstdlib_i486.so tier0_i486.so 
 
 OBJECTS = sdk/smsdk_ext.cpp extension.cpp gamerules.cpp vdecoder.cpp vcallbuilder.cpp \
 	vcaller.cpp vnatives.cpp vsound.cpp tenatives.cpp trnatives.cpp tempents.cpp