diff --git a/Makefile.am b/Makefile.am
index ba51594d..25d413e5 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -727,6 +727,9 @@ tesseract_CPPFLAGS += -I$(top_srcdir)/src/ccstruct
 tesseract_CPPFLAGS += -I$(top_srcdir)/src/ccutil
 tesseract_CPPFLAGS += -I$(top_srcdir)/src/dict
 tesseract_CPPFLAGS += -I$(top_srcdir)/src/viewer
+if OPENCL
+tesseract_CPPFLAGS += -I$(top_srcdir)/src/opencl
+endif
 tesseract_CPPFLAGS += $(AM_CPPFLAGS)
 if VISIBILITY
 tesseract_CPPFLAGS += -DTESS_IMPORTS
diff --git a/src/ccstruct/otsuthr.cpp b/src/ccstruct/otsuthr.cpp
index 68973941..ddceecfb 100644
--- a/src/ccstruct/otsuthr.cpp
+++ b/src/ccstruct/otsuthr.cpp
@@ -75,7 +75,7 @@ int OtsuThreshold(Image src_pix, int left, int top, int width, int height, std::
       // or to be a convincing background we must have a large fraction of H.
       // In between we assume this channel contains no thresholding information.
       int hi_value = best_omega_0 < H * 0.5;
-      (*thresholds)[ch] = best_t;
+      thresholds[ch] = best_t;
       if (best_omega_0 > H * 0.75) {
         any_good_hivalue = true;
         hi_values[ch] = 0;
diff --git a/src/opencl/openclwrapper.cpp b/src/opencl/openclwrapper.cpp
index 578f8f50..587a8c97 100644
--- a/src/opencl/openclwrapper.cpp
+++ b/src/opencl/openclwrapper.cpp
@@ -47,10 +47,14 @@
 #  endif
 
 #  include <cstdio>
+#  include <cstdlib>
 #  include <cstring> // for memset, strcpy, ...
 #  include <vector>
 
 #  include "errcode.h" // for ASSERT_HOST
+#  include "image.h"   // for Image
+
+namespace tesseract {
 
 GPUEnv OpenclDevice::gpuEnv;
 
@@ -2193,7 +2197,7 @@ static double getLineMasksMorphMicroBench(GPUEnv *env, TessScoreEvaluationInputD
 #  endif
     OpenclDevice::gpuEnv = *env;
     OpenclDevice::initMorphCLAllocations(wpl, input.height, input.pix);
-    Image pix_vline = nullptr, *pix_hline = nullptr, *pix_closed = nullptr;
+    Image pix_vline = nullptr, pix_hline = nullptr, pix_closed = nullptr;
     OpenclDevice::pixGetLinesCL(nullptr, input.pix, &pix_vline, &pix_hline, &pix_closed, true,
                                 closing_brick, closing_brick, max_line_width, max_line_width,
                                 min_line_length, min_line_length);
@@ -2252,8 +2256,6 @@ static double getLineMasksMorphMicroBench(GPUEnv *env, TessScoreEvaluationInputD
  * Device Selection
  *****************************************************************************/
 
-#  include <cstdlib>
-
 // encode score object as byte string
 static ds_status serializeScore(ds_device *device, uint8_t **serializedScore,
                                 unsigned int *serializedScoreSize) {
@@ -2453,4 +2455,6 @@ bool OpenclDevice::selectedDeviceIsOpenCL() {
   return (device.type == DS_DEVICE_OPENCL_DEVICE);
 }
 
+} // namespace
+
 #endif
diff --git a/src/opencl/openclwrapper.h b/src/opencl/openclwrapper.h
index 9360b0d5..fcf535ad 100644
--- a/src/opencl/openclwrapper.h
+++ b/src/opencl/openclwrapper.h
@@ -30,6 +30,9 @@
 #    include <CL/cl.h>
 #  endif
 
+namespace tesseract {
+
+class Image;
 struct TessDeviceScore;
 
 // device type
@@ -170,5 +173,7 @@ public:
   static bool selectedDeviceIsOpenCL();
 };
 
+}
+
 #endif // USE_OPENCL
 #endif // TESSERACT_OPENCL_OPENCLWRAPPER_H_