diff --git a/CMakeLists.txt b/CMakeLists.txt
index e41a5f77..df973738 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -28,7 +28,10 @@ enable_language(CXX)
 set(CMAKE_CXX_STANDARD 11)
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/cmake/Modules/" ${CMAKE_MODULE_PATH})
 
-set(CMAKE_INSTALL_PREFIX "${CMAKE_CURRENT_LIST_DIR}" CACHE PATH "Install prefix" FORCE)
+if (CMAKE_INSTALL_PREFIX_INITIALIZED_TO_DEFAULT)
+  set(CMAKE_INSTALL_PREFIX "${CMAKE_CURRENT_LIST_DIR}" CACHE PATH "Install prefix" FORCE)
+endif()
+
 set(INSTALL_BIN_DIR      "${CMAKE_CURRENT_LIST_DIR}" CACHE PATH "Path where exe and dll will be installed")
 set(INSTALL_LIB_DIR      "${CMAKE_CURRENT_LIST_DIR}" CACHE PATH "Path where lib will be installed")
 set(INSTALL_INCLUDE_DIR  "include/darknet"           CACHE PATH "Path where headers will be installed")
@@ -74,7 +77,9 @@ find_package(Threads REQUIRED)
 if(MSVC)
   find_package(PThreads_windows REQUIRED)
 endif()
-find_package(OpenCV)
+if(ENABLE_OPENCV)
+  find_package(OpenCV)
+endif()
 find_package(Stb REQUIRED)
 if(${CMAKE_VERSION} VERSION_LESS "3.9.0")
   message(WARNING "To build with OpenMP support you need CMake 3.9.0+")
diff --git a/src/detector.c b/src/detector.c
index 9501d105..074365fb 100644
--- a/src/detector.c
+++ b/src/detector.c
@@ -18,7 +18,7 @@ typedef __compar_fn_t comparison_fn_t;
 
 #include "http_stream.h"
 
-int check_mistakes;
+int check_mistakes = 0;
 
 static int coco_ids[] = { 1,2,3,4,5,6,7,8,9,10,11,13,14,15,16,17,18,19,20,21,22,23,24,25,27,28,31,32,33,34,35,36,37,38,39,40,41,42,43,44,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,67,70,72,73,74,75,76,77,78,79,80,81,82,84,85,86,87,88,89,90 };
 
@@ -996,7 +996,7 @@ float validate_detector_map(char *datacfg, char *cfgfile, char *weightfile, floa
 
         // MS COCO - uses 101-Recall-points on PR-chart.
         // PascalVOC2007 - uses 11-Recall-points on PR-chart.
-        // PascalVOC2010–2012 - uses Area-Under-Curve on PR-chart.
+        // PascalVOC2010-2012 - uses Area-Under-Curve on PR-chart.
         // ImageNet - uses Area-Under-Curve on PR-chart.
 
         // correct mAP calculation: ImageNet, PascalVOC 2010-2012