diff --git a/compiler/make/Makefile.compiler.head b/compiler/make/Makefile.compiler.head
index c5f2e27c4b48..7ee1efe2bc56 100644
--- a/compiler/make/Makefile.compiler.head
+++ b/compiler/make/Makefile.compiler.head
@@ -34,7 +34,7 @@ ifeq ($(ASSERTS),1)
   DYNO_ENABLE_ASSERTIONS = 1
 endif
 
-ifneq (, $(call isTrue, $(CHPL_DEVELOPER)))
+ifeq (, $(call isTrue, $(CHPL_DEVELOPER)))
 OPTIMIZE=1
 else
 DEBUG=1
diff --git a/modules/Makefile b/modules/Makefile
index 10a67e2d2c79..24ba3f8a4c3a 100644
--- a/modules/Makefile
+++ b/modules/Makefile
@@ -22,7 +22,7 @@ endif
 
 # Generate tags only if $TAGS turned on explicitly, or if $CHPL_DEVELOPER is on
 CHPL_DEVELOPER ?= 0
-ifeq (, $(call isTrue, $(CHPL_DEVELOPER)))
+ifneq (, $(call isTrue, $(CHPL_DEVELOPER)))
 TAGS=1
 endif
 
diff --git a/runtime/etc/Makefile.include b/runtime/etc/Makefile.include
index 5f872440c618..fb73626100b1 100644
--- a/runtime/etc/Makefile.include
+++ b/runtime/etc/Makefile.include
@@ -171,7 +171,7 @@ printmultilocalelibdeps:
 
 checkRtLibDir:
 ifeq ($(wildcard $(CHPL_RT_LIB_DIR)),)
-ifeq (, $(call isTrue, $(CHPL_DEVELOPER)))
+ifneq (, $(call isTrue, $(CHPL_DEVELOPER)))
 	$(warning Expected runtime library in $(CHPL_RT_LIB_DIR))
 endif
 ifeq ($(CHPL_MODULE_HOME),$(CHPL_HOME))
diff --git a/runtime/make/Makefile.runtime.head b/runtime/make/Makefile.runtime.head
index b08bf3400a42..2f5b341b4fab 100644
--- a/runtime/make/Makefile.runtime.head
+++ b/runtime/make/Makefile.runtime.head
@@ -21,7 +21,7 @@
 #
 DEPEND=1
 CHPL_DEVELOPER ?= 0
-ifeq (, $(call isTrue, $(CHPL_DEVELOPER)))
+ifneq (, $(call isTrue, $(CHPL_DEVELOPER)))
 DEBUG=1
 WARNINGS=1
 TAGS=1
diff --git a/third-party/Makefile b/third-party/Makefile
index 4cba8c6528a7..99de7c50406b 100644
--- a/third-party/Makefile
+++ b/third-party/Makefile
@@ -3,7 +3,7 @@ export CHPL_MAKE_HOME=$(shell pwd)/..
 endif
 include $(CHPL_MAKE_HOME)/make/Makefile.base
 
-ifeq (, $(call isTrue, $(CHPL_DEVELOPER)))
+ifneq (, $(call isTrue, $(CHPL_DEVELOPER)))
 DEBUG=1
 export DEBUG
 WARNINGS=1