diff --git a/win32/Makefile.gcc b/win32/Makefile.gcc
index fddd78a80c09fdfdcc73fc7ae802564966e12dc8..c4a6589ce30d9381269bfc659b6d5be928deb1ea 100644
--- a/win32/Makefile.gcc
+++ b/win32/Makefile.gcc
@@ -123,6 +123,10 @@ zlibrc.o: win32/zlib1.rc
 .PHONY: install uninstall clean
 
 install: zlib.h zconf.h $(STATICLIB) $(IMPLIB)
+	@if test -z "$(INCLUDE_PATH)" -o -z "$(LIBRARY_PATH)" -o -z "$(BINARY_PATH)"; then \
+		echo INCLUDE_PATH, LIBRARY_PATH, and BINARY_PATH must be specified; \
+		exit 1; \
+	fi
 	-@mkdir -p $(INCLUDE_PATH)
 	-@mkdir -p $(LIBRARY_PATH) $(LIBRARY_PATH)/pkgconfig
 	-if [ "$(SHARED_MODE)" = "1" ]; then \