--- a/src/extension/internal/pdfinput/pdf-input.cpp
+++ b/src/extension/internal/pdfinput/pdf-input.cpp
@@ -689,12 +689,12 @@
         //
         gchar const *poppler_datadir = g_getenv("POPPLER_DATADIR");
         if (poppler_datadir != NULL) {
-            globalParams = new GlobalParams(poppler_datadir);
+            globalParams = std::unique_ptr<GlobalParams>(new GlobalParams(poppler_datadir));
         } else {
-            globalParams = new GlobalParams();
+            globalParams = std::unique_ptr<GlobalParams>(new GlobalParams());
         }
 #else
-        globalParams = new GlobalParams();
+        globalParams = std::unique_ptr<GlobalParams>(new GlobalParams());
 #endif // ENABLE_OSX_APP_LOCATIONS
     }
 
--- a/src/extension/internal/pdfinput/pdf-parser.cpp
+++ b/src/extension/internal/pdfinput/pdf-parser.cpp
@@ -265,14 +265,14 @@
 class ClipHistoryEntry {
 public:
 
-    ClipHistoryEntry(GfxPath *clipPath = NULL, GfxClipType clipType = clipNormal);
+    ClipHistoryEntry(const GfxPath *clipPath = NULL, GfxClipType clipType = clipNormal);
     virtual ~ClipHistoryEntry();
 
     // Manipulate clip path stack
     ClipHistoryEntry *save();
     ClipHistoryEntry *restore();
     GBool hasSaves() { return saved != NULL; }
-    void setClip(GfxPath *newClipPath, GfxClipType newClipType = clipNormal);
+    void setClip(const GfxPath *newClipPath, GfxClipType newClipType = clipNormal);
     GfxPath *getClipPath() { return clipPath; }
     GfxClipType getClipType() { return clipType; }
 
@@ -3379,7 +3379,7 @@
 // ClipHistoryEntry
 //------------------------------------------------------------------------
 
-ClipHistoryEntry::ClipHistoryEntry(GfxPath *clipPathA, GfxClipType clipTypeA) :
+ClipHistoryEntry::ClipHistoryEntry(const GfxPath *clipPathA, GfxClipType clipTypeA) :
   saved(NULL),
   clipPath((clipPathA) ? clipPathA->copy() : NULL),
   clipType(clipTypeA)
@@ -3394,7 +3394,7 @@
     }
 }
 
-void ClipHistoryEntry::setClip(GfxPath *clipPathA, GfxClipType clipTypeA) {
+void ClipHistoryEntry::setClip(const GfxPath *clipPathA, GfxClipType clipTypeA) {
     // Free previous clip path
     if (clipPath) {
         delete clipPath;
--- a/src/extension/internal/pdfinput/svg-builder.cpp
+++ b/src/extension/internal/pdfinput/svg-builder.cpp
@@ -264,10 +264,10 @@
 /**
  * \brief Generates a SVG path string from poppler's data structure
  */
-static gchar *svgInterpretPath(GfxPath *path) {
+static gchar *svgInterpretPath(const GfxPath *path) {
     Inkscape::SVG::PathString pathString;
     for (int i = 0 ; i < path->getNumSubpaths() ; ++i ) {
-        GfxSubpath *subpath = path->getSubpath(i);
+        const GfxSubpath *subpath = path->getSubpath(i);
         if (subpath->getNumPoints() > 0) {
             pathString.moveTo(subpath->getX(0), subpath->getY(0));
             int j = 1;