diff --git a/CMakeLists.txt b/CMakeLists.txt
index 85d2f64ce..6583f7cd4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,7 +5,7 @@ list(APPEND CMAKE_MODULE_PATH ${ETH_CMAKE_DIR})
 
 # Set the build type, if none was specified.
 if(NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
-	if(EXISTS "${CMAKE_SOURCE_DIR}/.git")
+	if(EXISTS "${PROJECT_SOURCE_DIR}/.git")
 		set(DEFAULT_BUILD_TYPE "RelWithDebInfo")
 	else()
 		set(DEFAULT_BUILD_TYPE "Release")
@@ -66,12 +66,12 @@ include(EthUtils)
 
 # Create license.h from LICENSE.txt and template
 # Converting to char array is required due to MSVC's string size limit.
-file(READ ${CMAKE_SOURCE_DIR}/LICENSE.txt LICENSE_TEXT HEX)
+file(READ ${PROJECT_SOURCE_DIR}/LICENSE.txt LICENSE_TEXT HEX)
 string(REGEX MATCHALL ".." LICENSE_TEXT "${LICENSE_TEXT}")
 string(REGEX REPLACE ";" ",\n\t0x" LICENSE_TEXT "${LICENSE_TEXT}")
 set(LICENSE_TEXT "0x${LICENSE_TEXT}")
 
-configure_file("${CMAKE_SOURCE_DIR}/cmake/templates/license.h.in" include/license.h)
+configure_file("${PROJECT_SOURCE_DIR}/cmake/templates/license.h.in" include/license.h)
 
 include(EthOptions)
 configure_project(TESTS)
diff --git a/cmake/EthCompilerSettings.cmake b/cmake/EthCompilerSettings.cmake
index 4dd593458..6cfa864c1 100644
--- a/cmake/EthCompilerSettings.cmake
+++ b/cmake/EthCompilerSettings.cmake
@@ -28,7 +28,7 @@ if(PEDANTIC)
 endif()
 
 # Prevent the path of the source directory from ending up in the binary via __FILE__ macros.
-eth_add_cxx_compiler_flag_if_supported("-fmacro-prefix-map=${CMAKE_SOURCE_DIR}=/solidity")
+eth_add_cxx_compiler_flag_if_supported("-fmacro-prefix-map=${PROJECT_SOURCE_DIR}=/solidity")
 
 # -Wpessimizing-move warns when a call to std::move would prevent copy elision
 # if the argument was not wrapped in a call.  This happens when moving a local
diff --git a/cmake/fmtlib.cmake b/cmake/fmtlib.cmake
index 5ed196cea..2610424f6 100644
--- a/cmake/fmtlib.cmake
+++ b/cmake/fmtlib.cmake
@@ -3,7 +3,7 @@ include(FetchContent)
 FetchContent_Declare(
 	fmtlib
 	PREFIX "${CMAKE_BINARY_DIR}/deps"
-	DOWNLOAD_DIR "${CMAKE_SOURCE_DIR}/deps/downloads"
+	DOWNLOAD_DIR "${PROJECT_SOURCE_DIR}/deps/downloads"
 	DOWNLOAD_NAME fmt-8.0.1.tar.gz
 	URL https://github.com/fmtlib/fmt/archive/8.0.1.tar.gz
 	URL_HASH SHA256=b06ca3130158c625848f3fb7418f235155a4d389b2abc3a6245fb01cb0eb1e01
diff --git a/cmake/jsoncpp.cmake b/cmake/jsoncpp.cmake
index 29b8f5f05..48a9d2b49 100644
--- a/cmake/jsoncpp.cmake
+++ b/cmake/jsoncpp.cmake
@@ -42,7 +42,7 @@ endif()
 
 ExternalProject_Add(jsoncpp-project
     PREFIX "${prefix}"
-    DOWNLOAD_DIR "${CMAKE_SOURCE_DIR}/deps/downloads"
+    DOWNLOAD_DIR "${PROJECT_SOURCE_DIR}/deps/downloads"
     DOWNLOAD_NAME jsoncpp-1.9.3.tar.gz
     URL https://github.com/open-source-parsers/jsoncpp/archive/1.9.3.tar.gz
     URL_HASH SHA256=8593c1d69e703563d94d8c12244e2e18893eeb9a8a9f8aa3d09a327aa45c8f7d
diff --git a/cmake/range-v3.cmake b/cmake/range-v3.cmake
index 75ed5a92e..4f3225420 100644
--- a/cmake/range-v3.cmake
+++ b/cmake/range-v3.cmake
@@ -11,7 +11,7 @@ set(RANGE_V3_INCLUDE_DIR "${prefix}/include")
 
 ExternalProject_Add(range-v3-project
     PREFIX "${prefix}"
-    DOWNLOAD_DIR "${CMAKE_SOURCE_DIR}/deps/downloads"
+    DOWNLOAD_DIR "${PROJECT_SOURCE_DIR}/deps/downloads"
     DOWNLOAD_NAME range-v3-0.12.0.tar.gz
     URL https://github.com/ericniebler/range-v3/archive/0.12.0.tar.gz
     URL_HASH SHA256=015adb2300a98edfceaf0725beec3337f542af4915cec4d0b89fa0886f4ba9cb
diff --git a/libsolutil/CMakeLists.txt b/libsolutil/CMakeLists.txt
index b368e12f9..201429bb7 100644
--- a/libsolutil/CMakeLists.txt
+++ b/libsolutil/CMakeLists.txt
@@ -46,7 +46,7 @@ set(sources
 
 add_library(solutil ${sources})
 target_link_libraries(solutil PUBLIC jsoncpp Boost::boost Boost::filesystem Boost::system range-v3 fmt::fmt-header-only)
-target_include_directories(solutil PUBLIC "${CMAKE_SOURCE_DIR}")
+target_include_directories(solutil PUBLIC "${PROJECT_SOURCE_DIR}")
 add_dependencies(solutil solidity_BuildInfo.h)
 
 if(SOLC_LINK_STATIC)
diff --git a/libstdlib/CMakeLists.txt b/libstdlib/CMakeLists.txt
index a4523b99e..4a995c78f 100644
--- a/libstdlib/CMakeLists.txt
+++ b/libstdlib/CMakeLists.txt
@@ -1,18 +1,18 @@
 # This will re-generate the headers if any file within src was modified.
-set_directory_properties(PROPERTY CMAKE_CONFIGURE_DEPENDS ${CMAKE_SOURCE_DIR}/stdlib/src/)
+set_directory_properties(PROPERTY CMAKE_CONFIGURE_DEPENDS ${PROJECT_SOURCE_DIR}/stdlib/src/)
 
 set(STDLIB stub)
 set(GENERATED_STDLIB_HEADERS)
 foreach(src IN LISTS STDLIB)
-    set(STDLIB_FILE ${CMAKE_SOURCE_DIR}/libstdlib/src/${src}.sol)
+    set(STDLIB_FILE ${PROJECT_SOURCE_DIR}/libstdlib/src/${src}.sol)
     file(READ ${STDLIB_FILE} STDLIB_FILE_CONTENT HEX)
     string(REGEX MATCHALL ".." STDLIB_FILE_CONTENT "${STDLIB_FILE_CONTENT}")
     list(REMOVE_ITEM STDLIB_FILE_CONTENT "0d")
     string(REGEX REPLACE ";" ",\n\t0x" STDLIB_FILE_CONTENT "${STDLIB_FILE_CONTENT}")
     set(STDLIB_FILE_CONTENT "0x${STDLIB_FILE_CONTENT}")
     set(STDLIB_FILE_NAME ${src})
-    configure_file("${CMAKE_SOURCE_DIR}/libstdlib/stdlib.src.h.in" ${CMAKE_BINARY_DIR}/include/libstdlib/${src}.h NEWLINE_STYLE LF @ONLY)
+    configure_file("${PROJECT_SOURCE_DIR}/libstdlib/stdlib.src.h.in" ${CMAKE_BINARY_DIR}/include/libstdlib/${src}.h NEWLINE_STYLE LF @ONLY)
     list(APPEND GENERATED_STDLIB_HEADERS ${CMAKE_BINARY_DIR}/include/libstdlib/${src}.h)
 endforeach()
 
-configure_file("${CMAKE_SOURCE_DIR}/libstdlib/stdlib.h.in" ${CMAKE_BINARY_DIR}/include/libstdlib/stdlib.h NEWLINE_STYLE LF @ONLY)
+configure_file("${PROJECT_SOURCE_DIR}/libstdlib/stdlib.h.in" ${CMAKE_BINARY_DIR}/include/libstdlib/stdlib.h NEWLINE_STYLE LF @ONLY)