diff --git a/Makefile b/Makefile
index 1d74c92c..71be00fe 100644
--- a/Makefile
+++ b/Makefile
@@ -11,12 +11,18 @@ PROJECT = tildefriends
 BUILD_DIR ?= out
 UNAME_S := $(shell uname -s)
 UNAME_M := $(shell uname -m)
+
+ANDROID_SDK ?= ~/Android/Sdk
+
 ifeq ($(UNAME_S),Darwin)
 BUILD_TYPES := macosdebug macosrelease iosdebug iosrelease iossimdebug iossimrelease
-EXTRA_BUILD_TYPES :=
 else ifeq ($(UNAME_S),Linux)
 BUILD_TYPES := debug release
-EXTRA_BUILD_TYPES := windebug winrelease androiddebug androidrelease androiddebug-x86 androidrelease-x86 androiddebug-x86_64 androidrelease-x86_64 androiddebug-armv7a androidrelease-armv7a iosdebug iosrelease
+HAVE_ANDROID = $(if $(shell which $(ANDROID_SDK)/platform-tools/adb),1,0)
+HAVE_LINUX_IOS = $(if $(shell which deps/ios_toolchain/target/bin deps/ios_toolchain/target/bin/arm-apple-darwin11-clang),1,0)
+HAVE_WIN = $(if $(shell which x86_64-w64-mingw32-gcc-win32),1,0)
+else
+$(error Unexpected host platform $(UNAME_S).)
 endif
 
 CFLAGS += \
@@ -29,7 +35,6 @@ CFLAGS += \
 	-fno-exceptions \
 	-g
 
-ANDROID_SDK ?= ~/Android/Sdk
 ANDROID_BUILD_TOOLS := $(ANDROID_SDK)/build-tools/33.0.1
 ANDROID_PLATFORM := $(ANDROID_SDK)/platforms/android-33
 ANDROID_NDK ?= $(ANDROID_SDK)/ndk/23.1.7779620
@@ -52,12 +57,21 @@ ANDROID_TARGETS := \
 	$(ANDROID_X86_64_TARGETS) \
 	$(ANDROID_ARMV7A_TARGETS) \
 	$(ANDROID_ARM64_TARGETS)
-LINUX_TARGETS := \
-	out/debug/tildefriends \
-	out/release/tildefriends
+ifeq ($(HAVE_ANDROID),1)
+BUILD_TYPES += $(ANDROID_TARGETS)
+all: out/TildeFriends-debug.apk out/TildeFriends-release.apk
+endif
+
 WINDOWS_TARGETS := \
 	out/windebug/tildefriends.exe \
 	out/winrelease/tildefriends.exe
+ifeq ($(HAVE_WIN),1)
+BUILD_TYPES += windebug winrelease
+endif
+
+LINUX_TARGETS := \
+	out/debug/tildefriends \
+	out/release/tildefriends
 MACOS_TARGETS := \
 	out/macosdebug/tildefriends \
 	out/macosrelease/tildefriends
@@ -67,6 +81,18 @@ IOS_TARGETS := \
 IOSSIM_TARGETS := \
 	out/iossimdebug/tildefriends \
 	out/iossimrelease/tildefriends
+IOS_APPS = \
+	out/tildefriends-iosdebug.app/tildefriends \
+	out/tildefriends-iosrelease.app/tildefriends
+ifeq ($(HAVE_LINUX_IOS),1)
+BUILD_TYPES += iosdebug iosrelease
+all: $(IOS_APPS)
+endif
+ifeq ($(UNAME_S),Darwin)
+all: $(IOS_APPS) \
+	out/tildefriends-iossimdebug.app/tildefriends \
+	out/tildefriends-iossimrelease.app/tildefriends
+endif
 
 DEBUG_TARGETS := \
 	out/debug/tildefriends \
@@ -161,7 +187,7 @@ debug: LDFLAGS += -fsanitize=address -fsanitize=undefined
 endif
 
 get_objs = \
-	$(foreach build_type,$(BUILD_TYPES) $(EXTRA_BUILD_TYPES),$(addprefix $(BUILD_DIR)/$(build_type)/,$(addsuffix .o,$(basename $(value $(1)))))) \
+	$(foreach build_type,$(BUILD_TYPES),$(addprefix $(BUILD_DIR)/$(build_type)/,$(addsuffix .o,$(basename $(value $(1)))))) \
 	$(foreach build_type,debug release,$(addprefix $(BUILD_DIR)/$(build_type)/,$(addsuffix .o,$(basename $(value $(1)_unix))))) \
 	$(foreach build_type,windebug winrelease,$(addprefix $(BUILD_DIR)/$(build_type)/,$(addsuffix .o,$(basename $(value $(1)_win))))) \
 	$(foreach build_type,androiddebug androidrelease androiddebug-x86 androidrelease-x86 androiddebug-x86_64 androidrelease-x86_64 androiddebug-armv7a androiddebug-armv7a,$(addprefix $(BUILD_DIR)/$(build_type)/,$(addsuffix .o,$(basename $(value $(1)_android))))) \
@@ -523,12 +549,6 @@ $(IOS_TARGETS) $(IOSSIM_TARGETS): LDFLAGS += \
 unix: debug release
 win: windebug winrelease
 all: $(BUILD_TYPES)
-ifeq ($(UNAME_S),Linux)
-all: out/TildeFriends-debug.apk out/TildeFriends-release.apk
-endif
-ifeq ($(UNAME_S),Darwin)
-all: out/tildefriends-iosdebug.app/tildefriends out/tildefriends-iosrelease.app/tildefriends out/tildefriends-iossimdebug.app/tildefriends out/tildefriends-iossimrelease.app/tildefriends
-endif
 .PHONY: all win unix
 
 ALL_APP_OBJS := \
@@ -570,7 +590,7 @@ $(BUILD_DIR)/$(1)/%.o: %.S
 	@$$(AS) -c $$< -o $$@
 endef
 
-$(foreach build_type,$(BUILD_TYPES) $(EXTRA_BUILD_TYPES),$(eval $(call build_rules,$(build_type))))
+$(foreach build_type,$(BUILD_TYPES),$(eval $(call build_rules,$(build_type))))
 
 src/version.h : $(firstword $(MAKEFILE_LIST))
 	@echo [version] $@