diff --git a/CMakeLists.txt b/CMakeLists.txt
index 30f278223..c6c05523e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -34,6 +34,8 @@ if (NOT ${PYBIND11_PYTHON_VERSION} STREQUAL "")
 else()
   find_package(PythonLibs REQUIRED)
 endif()
+# The above sometimes returns version numbers like "3.4.3+"; the "+" must be removed for the next line to work
+string(REPLACE "+" "" PYTHONLIBS_VERSION_STRING "+${PYTHONLIBS_VERSION_STRING}")
 find_package(PythonInterp ${PYTHONLIBS_VERSION_STRING} EXACT REQUIRED)
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_CXX_COMPILER_ID MATCHES "GNU")
diff --git a/docs/cmake.rst b/docs/cmake.rst
index eb1f88544..238132f95 100644
--- a/docs/cmake.rst
+++ b/docs/cmake.rst
@@ -38,6 +38,9 @@ and that the pybind11 repository is located in a subdirectory named :file:`pybin
       find_package(PythonLibs REQUIRED)
     endif()
 
+    # The above sometimes returns version numbers like "3.4.3+"; the "+" must be removed for the next lines to work
+    string(REPLACE "+" "" PYTHONLIBS_VERSION_STRING "+${PYTHONLIBS_VERSION_STRING}")
+
     # Uncomment the following line if you will also require a matching Python interpreter
     # find_package(PythonInterp ${PYTHONLIBS_VERSION_STRING} EXACT REQUIRED)