diff --git a/codemeta.json b/codemeta.json
index a1e18792..c5462089 100644
--- a/codemeta.json
+++ b/codemeta.json
@@ -6,7 +6,7 @@
     "@type": "SoftwareSourceCode",
     "identifier": "colibricore",
     "name": "Colibri Core",
-    "version": "2.5.1",
+    "version": "2.5.2",
     "description": "Colibri core is an NLP tool as well as a C++ and Python library for working with basic linguistic constructions such as n-grams and skipgrams (i.e patterns with one or more gaps, either of fixed or dynamic size) in a quick and memory-efficient way. ",
     "license": "https://spdx.org/licenses/GPL-3.0",
 	"url": "https://proycon.github.io/colibri-core",
diff --git a/configure.ac b/configure.ac
index 2e0ee7c7..f87f3278 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4,7 +4,7 @@
 # $URL: https://ilk.uvt.nl/svn/sources/ucto/trunk/configure.ac $
 
 AC_PREREQ([2.67])
-AC_INIT([colibri-core],[2.5.1],[proycon@anaproy.nl])
+AC_INIT([colibri-core],[2.5.2],[proycon@anaproy.nl])
 AC_CONFIG_SRCDIR([configure.ac])
 AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_HEADER([config.h])
diff --git a/include/patternmodel.h b/include/patternmodel.h
index 22c938c4..abdaa574 100644
--- a/include/patternmodel.h
+++ b/include/patternmodel.h
@@ -3049,8 +3049,8 @@ class IndexedPatternModel: public PatternModel<IndexedData,IndexedDataHandler,Ma
 
                 if (((int) candidate.n() >= minsubsize)  && (candidate != pattern)
                         && ((occurrencethreshold == 0) || (this->occurrencecount(candidate) >= occurrencethreshold))
-                        && ((category == 0) || (candidate.category() >= category))
-                        && ((size == 0) || (candidate.n() >= size))
+                        && ((category == 0) || (candidate.category() == category))
+                        && ((size == 0) || (candidate.n() == size))
                     ) {
                     if ((candidate.category() == SKIPGRAM) || (pattern.category() == SKIPGRAM))  {
                         //instance may not have skips in places where the larger candidate pattern does
@@ -3100,8 +3100,8 @@ class IndexedPatternModel: public PatternModel<IndexedData,IndexedDataHandler,Ma
                 const PatternPointer neighbour = iter2->second;
                 if ((ref2.token + neighbour.n() == ref.token)
                         && ((occurrencethreshold == 0) || (this->occurrencecount(neighbour) >= occurrencethreshold))
-                        && ((category == 0) || (neighbour.category() >= category))
-                        && ((size == 0) || (neighbour.n() >= size))
+                        && ((category == 0) || (neighbour.category() == category))
+                        && ((size == 0) || (neighbour.n() == size))
                     ){
                     neighbours[neighbour]++;
                     if ((cutoff > 0) && (neighbours.size() >= cutoff)) break;
@@ -3141,8 +3141,8 @@ class IndexedPatternModel: public PatternModel<IndexedData,IndexedDataHandler,Ma
             for (std::unordered_set<PatternPointer>::iterator iter2 = rindex.begin(); iter2 != rindex.end(); iter2++) {
                 const PatternPointer neighbour = *iter2;
                 if ( ((occurrencethreshold == 0) || (this->occurrencecount(neighbour) >= occurrencethreshold))
-                        && ((category == 0) || (neighbour.category() >= category))
-                        && ((size == 0) || (neighbour.n() >= size)) ) {
+                        && ((category == 0) || (neighbour.category() == category))
+                        && ((size == 0) || (neighbour.n() == size)) ) {
                     neighbours[neighbour]++;
                     if ((cutoff > 0) && (neighbours.size() >= cutoff)) break;
                 }
@@ -3279,8 +3279,8 @@ class IndexedPatternModel: public PatternModel<IndexedData,IndexedDataHandler,Ma
                 const PatternPointer neighbour = iter2->second;
                 if ( (ref2.token > ref.token + _n)
                         && ((occurrencethreshold == 0) || (this->occurrencecount(neighbour) >= occurrencethreshold))
-                        && ((category == 0) || (neighbour.category() >= category))
-                        && ((size == 0) || (neighbour.n() >= size))
+                        && ((category == 0) || (neighbour.category() == category))
+                        && ((size == 0) || (neighbour.n() == size))
                      ) {
                     cooc[neighbour]++;
                     if (matches != NULL) matches->push_back(std::pair<IndexReference,IndexReference>(ref,ref2));
@@ -3322,8 +3322,8 @@ class IndexedPatternModel: public PatternModel<IndexedData,IndexedDataHandler,Ma
                 const int _n = neighbour.n();
                 if ( (ref2.token + _n < ref.token )
                         && ((occurrencethreshold == 0) || (this->occurrencecount(neighbour) >= occurrencethreshold))
-                        && ((category == 0) || (neighbour.category() >= category))
-                        && ((size == 0) || (neighbour.n() >= size))
+                        && ((category == 0) || (neighbour.category() == category))
+                        && ((size == 0) || (neighbour.n() == size))
                     ) {
                     cooc[neighbour]++;
                 }
@@ -3368,8 +3368,8 @@ class IndexedPatternModel: public PatternModel<IndexedData,IndexedDataHandler,Ma
                 const int _n2 = neighbour.n();
                 if ( ((ref2.token + _n2 < ref.token ) || (ref2.token > ref.token + _n))
                         && ((occurrencethreshold == 0) || (this->occurrencecount(neighbour) >= occurrencethreshold))
-                        && ((category == 0) || (neighbour.category() >= category))
-                        && ((size == 0) || (neighbour.n() >= size))
+                        && ((category == 0) || (neighbour.category() == category))
+                        && ((size == 0) || (neighbour.n() == size))
                     ) {
                     cooc[neighbour]++;
                 }
diff --git a/setup.py b/setup.py
index 2dc743b5..b067d298 100755
--- a/setup.py
+++ b/setup.py
@@ -183,7 +183,7 @@ def read(fname):
     license = "GPL",
     keywords = "nlp computational_linguistics frequency ngram skipgram pmi cooccurrence linguistics",
     long_description=read('README.rst'),
-    version = '2.5.1',
+    version = '2.5.2',
     ext_modules = extensions,
     cmdclass = {'build_ext': build_ext},
     classifiers=[