diff --git a/animation-server/CMakeLists.txt b/animation-server/CMakeLists.txt
index d8fa8d97b2..42516d2f86 100644
--- a/animation-server/CMakeLists.txt
+++ b/animation-server/CMakeLists.txt
@@ -30,4 +30,9 @@ link_hifi_library(octree ${TARGET_NAME} "${ROOT_DIR}")
 link_hifi_library(voxels ${TARGET_NAME} "${ROOT_DIR}")
 
 # link the hifi networking library
-link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
\ No newline at end of file
+link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/assignment-client/CMakeLists.txt b/assignment-client/CMakeLists.txt
index a088c04ffb..873ae761ca 100644
--- a/assignment-client/CMakeLists.txt
+++ b/assignment-client/CMakeLists.txt
@@ -46,3 +46,8 @@ IF (WIN32)
 ENDIF(WIN32)
 
 target_link_libraries(${TARGET_NAME} Qt5::Network Qt5::Widgets Qt5::Script)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/domain-server/CMakeLists.txt b/domain-server/CMakeLists.txt
index d1f923f4d2..f9bbeb31fc 100644
--- a/domain-server/CMakeLists.txt
+++ b/domain-server/CMakeLists.txt
@@ -42,4 +42,9 @@ IF (WIN32)
 ENDIF(WIN32)
 
 # link QtNetwork
-target_link_libraries(${TARGET_NAME} Qt5::Network)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} Qt5::Network)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/interface/CMakeLists.txt b/interface/CMakeLists.txt
index 67b993d6c9..cf203c41d9 100644
--- a/interface/CMakeLists.txt
+++ b/interface/CMakeLists.txt
@@ -285,6 +285,9 @@ else (APPLE)
     # we're using static GLEW, so define GLEW_STATIC
     add_definitions(-DGLEW_STATIC)
     
+    # add a definition for ssize_t so that windows doesn't bail
+    add_definitions(-Dssize_t=long)
+    
     target_link_libraries(${TARGET_NAME} "${GLEW_LIBRARY}" wsock32.lib opengl32.lib)
   endif()
 endif (APPLE)
diff --git a/libraries/animation/CMakeLists.txt b/libraries/animation/CMakeLists.txt
index 35ceb22395..1e33f50659 100644
--- a/libraries/animation/CMakeLists.txt
+++ b/libraries/animation/CMakeLists.txt
@@ -28,3 +28,8 @@ link_hifi_library(fbx ${TARGET_NAME} "${ROOT_DIR}")
 find_package(ZLIB)
 
 target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/audio/CMakeLists.txt b/libraries/audio/CMakeLists.txt
index 0bf0ba9904..60636ba051 100644
--- a/libraries/audio/CMakeLists.txt
+++ b/libraries/audio/CMakeLists.txt
@@ -21,4 +21,9 @@ include_glm(${TARGET_NAME} "${ROOT_DIR}")
 
 include(${MACRO_DIR}/LinkHifiLibrary.cmake)
 link_hifi_library(shared ${TARGET_NAME} "${ROOT_DIR}")
-link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
\ No newline at end of file
+link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/avatars/CMakeLists.txt b/libraries/avatars/CMakeLists.txt
index 9816282dda..fc398fc33d 100644
--- a/libraries/avatars/CMakeLists.txt
+++ b/libraries/avatars/CMakeLists.txt
@@ -28,4 +28,9 @@ link_hifi_library(octree ${TARGET_NAME} "${ROOT_DIR}")
 link_hifi_library(voxels ${TARGET_NAME} "${ROOT_DIR}")
 link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
 
-target_link_libraries(${TARGET_NAME} Qt5::Script)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} Qt5::Script)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/fbx/CMakeLists.txt b/libraries/fbx/CMakeLists.txt
index 9ce234bbd4..bc5ac3b3c4 100644
--- a/libraries/fbx/CMakeLists.txt
+++ b/libraries/fbx/CMakeLists.txt
@@ -29,3 +29,8 @@ find_package(ZLIB)
 
 include_directories(SYSTEM "${ZLIB_INCLUDE_DIRS}")
 target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/metavoxels/CMakeLists.txt b/libraries/metavoxels/CMakeLists.txt
index 7a8319815a..79c07c6c47 100644
--- a/libraries/metavoxels/CMakeLists.txt
+++ b/libraries/metavoxels/CMakeLists.txt
@@ -27,4 +27,9 @@ link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
 include(${MACRO_DIR}/IncludeGLM.cmake)
 include_glm(${TARGET_NAME} "${ROOT_DIR}")
 
-target_link_libraries(${TARGET_NAME} Qt5::Network Qt5::Widgets Qt5::Script)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} Qt5::Network Qt5::Widgets Qt5::Script)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/models/CMakeLists.txt b/libraries/models/CMakeLists.txt
index 7833349319..06578371cc 100644
--- a/libraries/models/CMakeLists.txt
+++ b/libraries/models/CMakeLists.txt
@@ -37,4 +37,9 @@ link_hifi_library(metavoxels ${TARGET_NAME} "${ROOT_DIR}")
 find_package(ZLIB)
 
 include_directories(SYSTEM "${ZLIB_INCLUDE_DIRS}")
-target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/networking/CMakeLists.txt b/libraries/networking/CMakeLists.txt
index f93ba2e5cf..fdd2d5830a 100644
--- a/libraries/networking/CMakeLists.txt
+++ b/libraries/networking/CMakeLists.txt
@@ -19,4 +19,9 @@ setup_hifi_library(${TARGET_NAME})
 include(${MACRO_DIR}/IncludeGLM.cmake)
 include_glm(${TARGET_NAME} "${ROOT_DIR}")
 
-target_link_libraries(${TARGET_NAME} Qt5::Network)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} Qt5::Network)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/octree/CMakeLists.txt b/libraries/octree/CMakeLists.txt
index 985b3fdba7..5988b4b058 100644
--- a/libraries/octree/CMakeLists.txt
+++ b/libraries/octree/CMakeLists.txt
@@ -28,4 +28,9 @@ link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
 find_package(ZLIB)
 
 include_directories(SYSTEM "${ZLIB_INCLUDE_DIRS}")
-target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/particles/CMakeLists.txt b/libraries/particles/CMakeLists.txt
index 7f42854b93..dbf2995293 100644
--- a/libraries/particles/CMakeLists.txt
+++ b/libraries/particles/CMakeLists.txt
@@ -32,3 +32,8 @@ find_package(ZLIB)
 
 include_directories(SYSTEM "${ZLIB_INCLUDE_DIRS}")
 target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/script-engine/CMakeLists.txt b/libraries/script-engine/CMakeLists.txt
index ac56f335e1..d0d05df286 100644
--- a/libraries/script-engine/CMakeLists.txt
+++ b/libraries/script-engine/CMakeLists.txt
@@ -34,3 +34,8 @@ find_package(ZLIB)
 
 include_directories(SYSTEM "${ZLIB_INCLUDE_DIRS}")
 target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/libraries/voxels/CMakeLists.txt b/libraries/voxels/CMakeLists.txt
index dd1020b4d7..51b83bb650 100644
--- a/libraries/voxels/CMakeLists.txt
+++ b/libraries/voxels/CMakeLists.txt
@@ -30,4 +30,9 @@ link_hifi_library(networking ${TARGET_NAME} "${ROOT_DIR}")
 find_package(ZLIB)
 
 include_directories(SYSTEM "${ZLIB_INCLUDE_DIRS}")
-target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets Qt5::Script)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} "${ZLIB_LIBRARIES}" Qt5::Widgets Qt5::Script)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file
diff --git a/voxel-edit/CMakeLists.txt b/voxel-edit/CMakeLists.txt
index ce3c542691..6ebf23efba 100644
--- a/voxel-edit/CMakeLists.txt
+++ b/voxel-edit/CMakeLists.txt
@@ -38,4 +38,9 @@ IF (WIN32)
 	target_link_libraries(${TARGET_NAME} Winmm Ws2_32)
 ENDIF(WIN32)
 
-target_link_libraries(${TARGET_NAME} Qt5::Script)
\ No newline at end of file
+target_link_libraries(${TARGET_NAME} Qt5::Script)
+
+# add a definition for ssize_t so that windows doesn't bail
+if (WIN32)
+  add_definitions(-Dssize_t=long)
+endif ()
\ No newline at end of file