diff --git a/config/config.mk b/config/config.mk
index df52066e58b..02b75137bb0 100644
--- a/config/config.mk
+++ b/config/config.mk
@@ -101,7 +101,7 @@ FINAL_TARGET ?= $(if $(XPI_NAME),$(DIST)/xpi-stage/$(XPI_NAME),$(DIST)/bin)$(DIS
 FINAL_TARGET_FROZEN := '$(FINAL_TARGET)'
 
 ifdef XPI_NAME
-ACDEFINES += -DXPI_NAME=$(XPI_NAME)
+DEFINES += -DXPI_NAME=$(XPI_NAME)
 endif
 
 # The VERSION_NUMBER is suffixed onto the end of the DLLs we ship.
@@ -533,7 +533,7 @@ sysinstall_cmd = install_cmd
 # overridden by the command line. (Besides, AB_CD is prettier).
 AB_CD = $(MOZ_UI_LOCALE)
 # Many locales directories want this definition.
-ACDEFINES += -DAB_CD=$(AB_CD)
+DEFINES += -DAB_CD=$(AB_CD)
 
 ifndef L10NBASEDIR
   L10NBASEDIR = $(error L10NBASEDIR not defined by configure)
@@ -689,3 +689,5 @@ export CL_INCLUDES_PREFIX
 # in environment variables to prevent it from breking silently on
 # non-English systems.
 export NONASCII
+
+DEFINES += -DNO_NSPR_10_SUPPORT
diff --git a/configure.in b/configure.in
index 990f8c80a48..512dffd9920 100644
--- a/configure.in
+++ b/configure.in
@@ -9172,9 +9172,6 @@ if test -z "$JS_SHARED_LIBRARY"; then
 fi
 AC_SUBST(JS_SHARED_LIBRARY)
 
-# Avoid using obsolete NSPR features
-AC_DEFINE(NO_NSPR_10_SUPPORT)
-
 MOZ_CREATE_CONFIG_STATUS()
 
 if test "$COMPILE_ENVIRONMENT"; then
diff --git a/js/src/configure.in b/js/src/configure.in
index 45c0a958250..37bff6341ab 100644
--- a/js/src/configure.in
+++ b/js/src/configure.in
@@ -3881,9 +3881,6 @@ fi
 MOZ_SUBCONFIGURE_FFI()
 MOZ_SUBCONFIGURE_JEMALLOC()
 
-# Avoid using obsolete NSPR features
-AC_DEFINE(NO_NSPR_10_SUPPORT)
-
 dnl Spit out some output
 dnl ========================================================
 MOZ_CREATE_CONFIG_STATUS()