diff --git a/build/targets.all.mak b/build/targets.all.mak
index e6d989add..1a48a316e 100644
--- a/build/targets.all.mak
+++ b/build/targets.all.mak
@@ -54,8 +54,8 @@ all_official:
 	$(Q) cp output/release/simulator/web/epsilon.official.js.mem output/all_official/epsilon.python.js.mem
 	$(Q) echo "BUILD_FIRMWARE    SIMULATOR ANDROID"
 	$(Q) $(MAKE) PLATFORM=simulator TARGET=android clean
-	$(Q) $(MAKE) PLATFORM=simulator TARGET=android epsilon.official.apk
-	$(Q) cp output/release/simulator/android/app/outputs/apk/release/android-release-unsigned.apk output/all_official/epsilon.apk
+	$(Q) $(MAKE) PLATFORM=simulator TARGET=android epsilon.official.signed.apk
+	$(Q) cp output/release/simulator/android/app/outputs/apk/codesigned/android-codesigned.apk output/all_official/epsilon.official.apk
 	$(Q) echo "BUILD_FIRMWARE    SIMULATOR IOS"
 	$(Q) $(MAKE) PLATFORM=simulator TARGET=ios clean
 	$(Q) $(MAKE) PLATFORM=simulator TARGET=ios IOS_PROVISIONNING_PROFILE=$(IOS_MOBILE_PROVISION) output/release/simulator/ios/app/epsilon.official.ipa
diff --git a/ion/src/simulator/android/Makefile b/ion/src/simulator/android/Makefile
index 0e6e70184..0a3d25619 100644
--- a/ion/src/simulator/android/Makefile
+++ b/ion/src/simulator/android/Makefile
@@ -68,14 +68,13 @@ $(eval $(call rule_for_gradle,assembleRelease,.official.))
 
 DEFAULT = epsilon.apk
 
-.PHONY: epsilon%apk
-ifdef ANDROID_SIGNING_STORE_FILE
-epsilon%apk: gradle_assembleCodesigned_%
-else
-epsilon%apk: gradle_assembleRelease_%
-	$(warning Building without code signing. Define ANDROID_SIGNING_STORE_FILE, ANDROID_SIGNING_STORE_PASSWORD, ANDROID_SIGNING_KEY_ALIAS and  ANDROID_SIGNING_KEY_PASSWORD for a signed build.)
-endif
+.PHONY: epsilon%signed.apk
+epsilon%signed.apk: gradle_assembleCodesigned_%
+	$(warning This is a signed build.)
 
+.PHONY: epsilon%apk
+epsilon%apk: gradle_assembleRelease_%
+	$(warning Building without code signing. Build epsilon$*signed.apk to generate a signed version.)
 
 .PHONY: epsilon_run
 epsilon_run: gradle_installDebug
diff --git a/ion/src/simulator/android/build.gradle b/ion/src/simulator/android/build.gradle
index 6a40c2927..531effaf0 100644
--- a/ion/src/simulator/android/build.gradle
+++ b/ion/src/simulator/android/build.gradle
@@ -1,5 +1,15 @@
 def BUILD_DIR = '../../../../'+System.getenv('BUILD_DIR')+'/app'
 
+def projectVariable(name) {
+  /* This function retrieves a variable from the environment and falls back
+   * to the Gradle projects's properties (e.g. ~/.gradle/gradle.properties) */
+  return System.getenv('ANDROID_'+name) ?: project.findProperty('EPSILON_'+name)
+}
+
+def fileIfPath(path) {
+  return path ? new File(path) : null
+}
+
 buildscript {
   repositories {
     jcenter()
@@ -33,10 +43,10 @@ android {
   }
   signingConfigs {
     environment {
-      storeFile System.getenv('ANDROID_SIGNING_STORE_FILE') ? new File(System.getenv('RELEASE_STORE_FILE')) : null
-      storePassword System.getenv('ANDROID_SIGNING_STORE_PASSWORD')
-      keyAlias System.getenv('ANDROID_SIGNING_KEY_ALIAS')
-      keyPassword System.getenv('ANDROID_SIGNING_KEY_PASSWORD')
+      storeFile fileIfPath(projectVariable('SIGNING_STORE_FILE'))
+      storePassword projectVariable('SIGNING_STORE_PASSWORD')
+      keyAlias projectVariable('SIGNING_KEY_ALIAS')
+      keyPassword projectVariable('SIGNING_KEY_PASSWORD')
     }
   }
   buildTypes {
diff --git a/ion/src/simulator/ios/Makefile b/ion/src/simulator/ios/Makefile
index c19966b28..57e1cf41e 100644
--- a/ion/src/simulator/ios/Makefile
+++ b/ion/src/simulator/ios/Makefile
@@ -87,10 +87,10 @@ simulator_app_deps += $(call simulator_app_resource,$(1), \
   launch.storyboardc \
 )
 
-$(BUILD_DIR)/app/epsilon%ipa: $(subst ..,.,$(call simulator_app_deps,Epsilon$*))
+$(BUILD_DIR)/app/epsilon%ipa: $$(subst ..,.,$$(call simulator_app_deps,Epsilon$$*))
 ifdef IOS_PROVISIONNING_PROFILE
 	$(call rule_label,SIGN)
-	$(Q) codesign --force --entitlements $(BUILD_DIR)/app/entitlements.plist --sign "Apple Distribution: NumWorks" $(BUILD_DIR)/app/Payload/Epsilon.app
+	$(Q) codesign --force --entitlements $(BUILD_DIR)/app/entitlements.plist --sign "Apple Distribution: NumWorks" $(BUILD_DIR)/app/Payload/Epsilon$*app
 endif
 	$(call rule_label,ZIP)
 	$(Q) cd $(dir $@) ; zip -qr9 $(notdir $@) Payload