diff --git a/viewer/CMakeLists.txt b/viewer/CMakeLists.txt
index 3d3d07d..99e4186 100644
--- a/viewer/CMakeLists.txt
+++ b/viewer/CMakeLists.txt
@@ -53,6 +53,9 @@ if(EMV_VIEWER_IS_TOP_LEVEL)
 		if(NOT EXISTS ${MCC_JSON_SOURCE_PATH})
 			message(FATAL_ERROR "mcc-codes/mcc_codes.json not found")
 		endif()
+
+		# Use relative data paths for MacOS bundles
+		set(EMV_VIEWER_USE_RELATIVE_DATA_PATH "../Resources/")
 	endif()
 else()
 	# Parent project must provide the emv-utils targets
@@ -67,6 +70,14 @@ else()
 	if(NOT EXISTS ${MCC_JSON_SOURCE_PATH})
 		message(FATAL_ERROR "mcc_codes.json not found")
 	endif()
+
+	# All-in-builds intended for installers should use relative data paths
+	if(APPLE AND BUILD_MACOSX_BUNDLE)
+		set(EMV_VIEWER_USE_RELATIVE_DATA_PATH "../Resources/")
+	endif()
+	if(WIN32)
+		set(EMV_VIEWER_USE_RELATIVE_DATA_PATH "../${CMAKE_INSTALL_DATADIR}/emv-utils/")
+	endif()
 endif()
 
 include(FindPackageHandleStandardArgs) # Provides find_package() messages
@@ -184,21 +195,25 @@ if(APPLE AND BUILD_MACOSX_BUNDLE)
 	)
 
 	# Install iso-codes into bundle for MacOS
-	find_package(IsoCodes REQUIRED)
-	install(FILES
-		${IsoCodes_JSON_PATH}/iso_639-2.json
-		${IsoCodes_JSON_PATH}/iso_3166-1.json
-		${IsoCodes_JSON_PATH}/iso_4217.json
-		COMPONENT emv_viewer_bundle
-		DESTINATION $<TARGET_BUNDLE_CONTENT_DIR:emv-viewer>/Resources/
-	)
+	if(EMV_VIEWER_USE_RELATIVE_DATA_PATH)
+		find_package(IsoCodes REQUIRED)
+		install(FILES
+			${IsoCodes_JSON_PATH}/iso_639-2.json
+			${IsoCodes_JSON_PATH}/iso_3166-1.json
+			${IsoCodes_JSON_PATH}/iso_4217.json
+			COMPONENT emv_viewer_bundle
+			DESTINATION $<TARGET_BUNDLE_CONTENT_DIR:emv-viewer>/Resources/
+		)
+	endif()
 
 	# Install mcc-codes into bundle for MacOS
-	install(FILES
-		${MCC_JSON_SOURCE_PATH}
-		COMPONENT emv_viewer_bundle
-		DESTINATION $<TARGET_BUNDLE_CONTENT_DIR:emv-viewer>/Resources/
-	)
+	if(EMV_VIEWER_USE_RELATIVE_DATA_PATH)
+		install(FILES
+			${MCC_JSON_SOURCE_PATH}
+			COMPONENT emv_viewer_bundle
+			DESTINATION $<TARGET_BUNDLE_CONTENT_DIR:emv-viewer>/Resources/
+		)
+	endif()
 
 	# Install other tools into bundle for MacOS
 	if(TARGET emv-decode)
@@ -233,14 +248,16 @@ if(WIN32)
 	target_sources(emv-viewer PRIVATE icon.rc)
 
 	# Install iso-codes for Windows
-	find_package(IsoCodes REQUIRED)
-	install(FILES
-		${IsoCodes_JSON_PATH}/iso_639-2.json
-		${IsoCodes_JSON_PATH}/iso_3166-1.json
-		${IsoCodes_JSON_PATH}/iso_4217.json
-		COMPONENT emv_runtime # Same as for mcc-codes
-		DESTINATION ${CMAKE_INSTALL_DATADIR}/emv-utils/ # Same as for mcc-codes
-	)
+	if(EMV_VIEWER_USE_RELATIVE_DATA_PATH)
+		find_package(IsoCodes REQUIRED)
+		install(FILES
+			${IsoCodes_JSON_PATH}/iso_639-2.json
+			${IsoCodes_JSON_PATH}/iso_3166-1.json
+			${IsoCodes_JSON_PATH}/iso_4217.json
+			COMPONENT emv_runtime # Same as for mcc-codes
+			DESTINATION ${CMAKE_INSTALL_DATADIR}/emv-utils/ # Same as for mcc-codes
+		)
+	endif()
 
 	# Deploy Qt for Windows
 	include(DeployQt)
diff --git a/viewer/emv-viewer.cpp b/viewer/emv-viewer.cpp
index 8ed4385..9cc5f94 100644
--- a/viewer/emv-viewer.cpp
+++ b/viewer/emv-viewer.cpp
@@ -21,6 +21,7 @@
 #include <QtWidgets/QApplication>
 #include <QtCore/QCommandLineParser>
 #include <QtCore/QString>
+#include <QtCore/QStringLiteral>
 
 #include "emv_viewer_config.h"
 #include "emv_strings.h"
@@ -50,6 +51,19 @@ int main(int argc, char** argv)
 
 	QString isocodes_path = parser.value("isocodes-path");
 	QString mcc_path = parser.value("mcc-json");
+#ifdef EMV_VIEWER_USE_RELATIVE_DATA_PATH
+	if (isocodes_path.isEmpty()) {
+		isocodes_path =
+			app.applicationDirPath() + QStringLiteral("/") +
+			QStringLiteral(EMV_VIEWER_USE_RELATIVE_DATA_PATH);
+	}
+	if (mcc_path.isEmpty()) {
+		mcc_path =
+			app.applicationDirPath() + QStringLiteral("/") +
+			QStringLiteral(EMV_VIEWER_USE_RELATIVE_DATA_PATH) +
+			QStringLiteral("mcc_codes.json");
+	}
+#endif
 	r = emv_strings_init(
 		isocodes_path.isEmpty() ? nullptr : qPrintable(isocodes_path),
 		mcc_path.isEmpty() ? nullptr : qPrintable(mcc_path)
diff --git a/viewer/emv_viewer_config.h.in b/viewer/emv_viewer_config.h.in
index 951afb6..b6716e7 100644
--- a/viewer/emv_viewer_config.h.in
+++ b/viewer/emv_viewer_config.h.in
@@ -21,5 +21,6 @@
 #define EMV_VIEWER_CONFIG_H
 
 #define EMV_VIEWER_VERSION_STRING "@EMV_UTILS_VERSION_STRING@"
+#cmakedefine EMV_VIEWER_USE_RELATIVE_DATA_PATH "@EMV_VIEWER_USE_RELATIVE_DATA_PATH@"
 
 #endif