diff --git a/src/ccmain/paragraphs_internal.h b/src/ccmain/paragraphs_internal.h
index a7c08d5110..558245af34 100644
--- a/src/ccmain/paragraphs_internal.h
+++ b/src/ccmain/paragraphs_internal.h
@@ -79,6 +79,13 @@ struct LineHypothesis {
   LineHypothesis(const LineHypothesis &other)
       : ty(other.ty), model(other.model) {}
 
+  // Copy assignment operator.
+  LineHypothesis& operator=(const LineHypothesis& other) {
+    ty = other.ty;
+    model = other.model;
+    return *this;
+  }
+
   bool operator==(const LineHypothesis &other) const {
     return ty == other.ty && model == other.model;
   }
diff --git a/src/ccstruct/blamer.h b/src/ccstruct/blamer.h
index 865ad5f107..b1b325b415 100644
--- a/src/ccstruct/blamer.h
+++ b/src/ccstruct/blamer.h
@@ -289,6 +289,8 @@ struct BlamerBundle {
   void SetMisAdaptionDebug(const WERD_CHOICE *best_choice, bool debug);
 
  private:
+  // Copy assignment operator (currently unused, therefore private).
+  BlamerBundle& operator=(const BlamerBundle& other);
   void SetBlame(IncorrectResultReason irr, const STRING &msg,
                 const WERD_CHOICE *choice, bool debug) {
     incorrect_result_reason_ = irr;
diff --git a/src/ccstruct/ocrrow.h b/src/ccstruct/ocrrow.h
index 878f3a0e35..3ab22c3644 100644
--- a/src/ccstruct/ocrrow.h
+++ b/src/ccstruct/ocrrow.h
@@ -144,6 +144,9 @@ class ROW:public ELIST_LINK
     ROW& operator= (const ROW & source);
 
   private:
+    // Copy constructor (currently unused, therefore private).
+    ROW(const ROW& source);
+
     int32_t kerning;               //inter char gap
     int32_t spacing;               //inter word gap
     TBOX bound_box;              //bounding box
diff --git a/src/ccstruct/params_training_featdef.h b/src/ccstruct/params_training_featdef.h
index 1cd5076e34..16a20e4e5d 100644
--- a/src/ccstruct/params_training_featdef.h
+++ b/src/ccstruct/params_training_featdef.h
@@ -105,14 +105,19 @@ int ParamsTrainingFeatureByName(const char *name);
 // Entry with features extracted from a single OCR hypothesis for a word.
 struct ParamsTrainingHypothesis {
   ParamsTrainingHypothesis() : cost(0.0) {
-    memset(features, 0, sizeof(float) * PTRAIN_NUM_FEATURE_TYPES);
+    memset(features, 0, sizeof(features));
   }
   ParamsTrainingHypothesis(const ParamsTrainingHypothesis &other) {
-    memcpy(features, other.features,
-           sizeof(float) * PTRAIN_NUM_FEATURE_TYPES);
+    memcpy(features, other.features, sizeof(features));
     str = other.str;
     cost = other.cost;
   }
+  ParamsTrainingHypothesis& operator=(const ParamsTrainingHypothesis& other) {
+    memcpy(features, other.features, sizeof(features));
+    str = other.str;
+    cost = other.cost;
+    return *this;
+  }
   float features[PTRAIN_NUM_FEATURE_TYPES];
   STRING str;  // string corresponding to word hypothesis (for debugging)
   float cost;  // path cost computed by segsearch
diff --git a/src/ccstruct/ratngs.cpp b/src/ccstruct/ratngs.cpp
index b61cf55294..aa3788a3af 100644
--- a/src/ccstruct/ratngs.cpp
+++ b/src/ccstruct/ratngs.cpp
@@ -129,6 +129,24 @@ BLOB_CHOICE::BLOB_CHOICE(const BLOB_CHOICE &other) : ELIST_LINK(other) {
   fonts_ = other.fonts_;
 }
 
+// Copy assignment operator.
+BLOB_CHOICE& BLOB_CHOICE::operator=(const BLOB_CHOICE& other) {
+  ELIST_LINK::operator=(other);
+  unichar_id_ = other.unichar_id();
+  rating_ = other.rating();
+  certainty_ = other.certainty();
+  fontinfo_id_ = other.fontinfo_id();
+  fontinfo_id2_ = other.fontinfo_id2();
+  script_id_ = other.script_id();
+  matrix_cell_ = other.matrix_cell_;
+  min_xheight_ = other.min_xheight_;
+  max_xheight_ = other.max_xheight_;
+  yshift_ = other.yshift();
+  classifier_ = other.classifier_;
+  fonts_ = other.fonts_;
+  return *this;
+}
+
 // Returns true if *this and other agree on the baseline and x-height
 // to within some tolerance based on a given estimate of the x-height.
 bool BLOB_CHOICE::PosAndSizeAgree(const BLOB_CHOICE& other, float x_height,
diff --git a/src/ccstruct/ratngs.h b/src/ccstruct/ratngs.h
index 18b2ac8ce7..4e3c6772d7 100644
--- a/src/ccstruct/ratngs.h
+++ b/src/ccstruct/ratngs.h
@@ -197,6 +197,9 @@ class BLOB_CHOICE: public ELIST_LINK
     }
 
  private:
+  // Copy assignment operator.
+  BLOB_CHOICE& operator=(const BLOB_CHOICE& other);
+
   UNICHAR_ID unichar_id_;          // unichar id
   // Fonts and scores. Allowed to be empty.
   GenericVector<tesseract::ScoredFont> fonts_;
diff --git a/src/textord/fpchop.h b/src/textord/fpchop.h
index 0bcfb2cf33..4cda239d5a 100644
--- a/src/textord/fpchop.h
+++ b/src/textord/fpchop.h
@@ -52,6 +52,8 @@ class C_OUTLINE_FRAG:public ELIST_LINK
     int16_t ycoord;                //coord of cut pt
 
   private:
+    // Copy constructor (currently unused, therefore private).
+    C_OUTLINE_FRAG(const C_OUTLINE_FRAG& other);
 };
 
 ELISTIZEH(C_OUTLINE_FRAG)