diff --git a/Makefile b/Makefile
index c968241..a66a47e 100644
--- a/Makefile
+++ b/Makefile
@@ -38,7 +38,10 @@ devicehub_image := ${project}/devicehub:${devicehub_tag}
 # idhub image tag
 ####
 
-idhub_branch := `git -C IdHub branch --show-current`
+# src https://stackoverflow.com/questions/33479645/substitute-character-in-makefile-variable-after-evaluation
+idhub_branch_raw := $(shell git -C IdHub branch --show-current)
+idhub_branch := $(subst /,-,$(idhub_branch_raw))
+
 idhub_commit := `git -C IdHub log -1 --format=%h`
 idhub_tag := ${idhub_branch}__${idhub_commit}
 idhub_tag := latest