diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 523ee42db0c8..7ef7cf04a292 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -182,7 +182,7 @@ $(OUTPUT)test-libaudit.bin:
 	$(BUILD) -laudit
 
 $(OUTPUT)test-libslang.bin:
-	$(BUILD) -I/usr/include/slang -lslang
+	$(BUILD) -lslang
 
 $(OUTPUT)test-libcrypto.bin:
 	$(BUILD) -lcrypto
diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 5f16a20cae86..e04b7a81d221 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -648,7 +648,6 @@ ifndef NO_SLANG
     NO_SLANG := 1
   else
     # Fedora has /usr/include/slang/slang.h, but ubuntu /usr/include/slang.h
-    CFLAGS += -I/usr/include/slang
     CFLAGS += -DHAVE_SLANG_SUPPORT
     EXTLIBS += -lslang
     $(call detected,CONFIG_SLANG)