diff --git a/src/Makefile b/src/Makefile
index 66b64d732..5ac8ed7bd 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -26,10 +26,12 @@ LD65_OBJ = $(datadir)/lib
 LD65_CFG = $(datadir)/cfg
 
 CFLAGS += -MMD -MP -O -std=c89 -D_SVID_SOURCE -I common \
-          -Wall -Wextra -Wno-char-subscripts -Werror $(USER_CFLAGS) \
+          -Wall -Wextra -Wno-char-subscripts $(USER_CFLAGS) \
           -DCA65_INC=$(CA65_INC) -DCC65_INC=$(CC65_INC) \
           -DLD65_LIB=$(LD65_LIB) -DLD65_OBJ=$(LD65_OBJ) -DLD65_CFG=$(LD65_CFG)
 
+CFLAGS += $(if $(TRAVIS),-Werror)
+
 LDLIBS += -lm
 
 INSTALL = install