diff --git a/src/hotspot/share/gc/shared/generationSpec.hpp b/src/hotspot/share/gc/shared/generationSpec.hpp
index 2933551a78..f943d83c47 100644
--- a/src/hotspot/share/gc/shared/generationSpec.hpp
+++ b/src/hotspot/share/gc/shared/generationSpec.hpp
@@ -44,6 +44,7 @@ public:
   GenerationSpec(Generation::Name name, size_t init_size, size_t max_size, size_t alignment) :
     _name(name),
     _init_size(align_up(init_size, alignment)),
+    _min_size(_init_size),
     _max_size(align_up(max_size, alignment))
   { }
 
diff --git a/test/hotspot/jtreg/serviceability/tmtools/jstat/utils/JstatGcCapacityResults.java b/test/hotspot/jtreg/serviceability/tmtools/jstat/utils/JstatGcCapacityResults.java
index 350a2a6470..8f81be763b 100644
--- a/test/hotspot/jtreg/serviceability/tmtools/jstat/utils/JstatGcCapacityResults.java
+++ b/test/hotspot/jtreg/serviceability/tmtools/jstat/utils/JstatGcCapacityResults.java
@@ -70,6 +70,7 @@ public class JstatGcCapacityResults extends JstatResults {
 
         // Check Young Gen consistency
         float NGCMN = getFloatValue("NGCMN");
+        assertThat(NGCMN >= 0, "NGCMN < 0 (min generation capacity is negative)");
         float NGCMX = getFloatValue("NGCMX");
         assertThat(NGCMX >= NGCMN, "NGCMN > NGCMX (min generation capacity > max generation capacity)");
 
@@ -102,6 +103,7 @@ public class JstatGcCapacityResults extends JstatResults {
 
         // Check Old Gen consistency
         float OGCMN = getFloatValue("OGCMN");
+        assertThat(OGCMN >= 0, "OGCMN < 0 (min generation capacity is negative)");
         float OGCMX = getFloatValue("OGCMX");
         assertThat(OGCMX >= OGCMN, "OGCMN > OGCMX (min generation capacity > max generation capacity)");