diff --git a/Makefile b/Makefile
index 6585ca39f..300873803 100644
--- a/Makefile
+++ b/Makefile
@@ -60,8 +60,8 @@ else
 	LDLIBS += -lrt
 endif
 
-YOSYS_VER := 0.5+$(shell test -d .git && { git log --author=clifford@clifford.at --oneline c3c9fbfb8c678.. | wc -l; })
-GIT_REV := $(shell git rev-parse --short HEAD 2> /dev/null || echo UNKNOWN)
+YOSYS_VER := 0.5+$(shell cd $(YOSYS_SRC) && test -d .git && { git log --author=clifford@clifford.at --oneline c3c9fbfb8c678.. | wc -l; })
+GIT_REV := $(shell cd $(YOSYS_SRC) && git rev-parse --short HEAD 2> /dev/null || echo UNKNOWN)
 OBJS = kernel/version_$(GIT_REV).o
 
 # set 'ABCREV = default' to use abc/ as it is