diff --git a/CMakeLists.txt b/CMakeLists.txt
index 780a437baf7..299ff9f096a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -27,6 +27,9 @@ if(POLICY CMP0056)
     cmake_policy(SET CMP0056 NEW)
 endif()
 
+# build the sdk targets
+project("aws-cpp-sdk-all" VERSION "${PROJECT_VERSION}" LANGUAGES CXX)
+
 # 3.0 or higher is strongly suggested; build settings (target_compile_options/etc...) sometimes do not get propagated properly under certain conditions prior to this version
 # Making this a hard requirement is potentially disruptive to existing customers who aren't affected by the bad behavior though, so just warn for now
 if(CMAKE_MAJOR_VERSION LESS 3)
@@ -165,6 +168,9 @@ if (BUILD_DEPS)
             -DBUILD_SHARED_LIBS=${BUILD_SHARED_LIBS}
             -DCMAKE_INSTALL_PREFIX=${AWS_DEPS_INSTALL_DIR}
             -DCMAKE_RUNTIME_OUTPUT_DIRECTORY=${CMAKE_CURRENT_BINARY_DIR}/bin
+            -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
+            -DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}
+            -DCMAKE_SYSTEM_NAME=${CMAKE_SYSTEM_NAME}
             ${CMAKE_CURRENT_SOURCE_DIR}/third-party
             WORKING_DIRECTORY ${AWS_DEPS_BUILD_DIR}
             RESULT_VARIABLE BUILD_3P_EXIT_CODE)
@@ -183,9 +189,6 @@ if (BUILD_DEPS)
     list(APPEND CMAKE_PREFIX_PATH "${AWS_DEPS_INSTALL_DIR}")
 endif()
 
-# build the sdk targets
-project("aws-cpp-sdk-all" VERSION "${PROJECT_VERSION}" LANGUAGES CXX)
-
 # http client, encryption, zlib
 include(external_dependencies)
 
diff --git a/third-party/cmake/BuildAwsCCommon.cmake b/third-party/cmake/BuildAwsCCommon.cmake
index 8569751d944..813147426f8 100644
--- a/third-party/cmake/BuildAwsCCommon.cmake
+++ b/third-party/cmake/BuildAwsCCommon.cmake
@@ -48,5 +48,6 @@ else()
         -DBUILD_SHARED_LIBS=${BUILD_SHARED_LIBS}
         -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
         -DCMAKE_RUNTIME_OUTPUT_DIRECTORY=${CMAKE_RUNTIME_OUTPUT_DIRECTORY}
+        -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
         )
 endif()
diff --git a/third-party/cmake/BuildAwsChecksums.cmake b/third-party/cmake/BuildAwsChecksums.cmake
index d1fcf9e5c21..c8ecc01ac38 100644
--- a/third-party/cmake/BuildAwsChecksums.cmake
+++ b/third-party/cmake/BuildAwsChecksums.cmake
@@ -47,6 +47,7 @@ else()
         -DBUILD_SHARED_LIBS=${BUILD_SHARED_LIBS}
         -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
         -DCMAKE_RUNTIME_OUTPUT_DIRECTORY=${CMAKE_RUNTIME_OUTPUT_DIRECTORY}
+        -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
         )
 endif()
 
diff --git a/third-party/cmake/BuildAwsEventStream.cmake b/third-party/cmake/BuildAwsEventStream.cmake
index 49590fccef8..c1ae0db1904 100644
--- a/third-party/cmake/BuildAwsEventStream.cmake
+++ b/third-party/cmake/BuildAwsEventStream.cmake
@@ -56,5 +56,6 @@ else()
         -DCMAKE_INSTALL_RPATH=${DEPS_RPATH}
         -DCMAKE_TOOLCHAIN_FILE=${CMAKE_TOOLCHAIN_FILE}
         -DCMAKE_RUNTIME_OUTPUT_DIRECTORY=${CMAKE_RUNTIME_OUTPUT_DIRECTORY}
+        -DCMAKE_C_FLAGS=${CMAKE_C_FLAGS}
         )
 endif()