diff --git a/Makefile b/Makefile
index 41730ce25d..6c3f596546 100644
--- a/Makefile
+++ b/Makefile
@@ -56,9 +56,12 @@ endif
 # directory build/px4_fmu-v2_default and then call make
 # in that directory with the target upload.
 
-#  explicity set default build target
+# explicity set default build target
 all: px4_sitl_default
 
+# define a space character to be able to explicitly find it in strings
+space := $(subst ,, )
+
 # Parsing
 # --------------------------------------------------------------------
 # assume 1st argument passed is the main target, the
@@ -165,8 +168,8 @@ define cmake-cache-check
 	@$(eval CACHED_CMAKE_OPTIONS = $(shell cd $(BUILD_DIR) 2>/dev/null && cmake -L 2>/dev/null | sed -n 's/\([^[:blank:]]*\):[^[:blank:]]*\(=[^[:blank:]]*\)/\1\2/gp' ))
 	@# transform the options in CMAKE_ARGS into the OPTION=VALUE format without -D
 	@$(eval DESIRED_CMAKE_OPTIONS = $(shell echo $(CMAKE_ARGS) | sed -n 's/-D\([^[:blank:]]*=[^[:blank:]]*\)/\1/gp' ))
-	@# find each currently desired option in the already cached ones
-	@$(eval VERIFIED_CMAKE_OPTIONS = $(foreach option,$(DESIRED_CMAKE_OPTIONS),$(findstring $(option),$(CACHED_CMAKE_OPTIONS))))
+	@# find each currently desired option in the already cached ones making sure the complete configured string value is the same
+	@$(eval VERIFIED_CMAKE_OPTIONS = $(foreach option,$(DESIRED_CMAKE_OPTIONS),$(strip $(findstring $(option)$(space),$(CACHED_CMAKE_OPTIONS)))))
 	@# if the complete list of desired options is found in the list of verified options we don't need to reconfigure and CMAKE_CACHE_CHECK stays empty
 	@$(eval CMAKE_CACHE_CHECK = $(if $(findstring $(DESIRED_CMAKE_OPTIONS),$(VERIFIED_CMAKE_OPTIONS)),,y))
 endef
@@ -474,7 +477,6 @@ distclean: gazeboclean
 		$(error "$@ cannot be the first argument. Use '$(MAKE) help|list_config_targets' to get a list of all possible [configuration] targets."),@#)
 
 # Print a list of non-config targets (based on http://stackoverflow.com/a/26339924/1487069)
-space := $(subst ,, )
 help:
 	@echo "Usage: $(MAKE) <target>"
 	@echo "Where <target> is one of:"