diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09add7ca..6fdd16d9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,4 @@
+- Fixed session tab blocking resize below ~600px when docked as a side panel (https://github.com/nbclaudecodegui/NetbeansClaudeCodeGui/issues/19)
 - Fixed terminal appearing blank after dismissing the model selection menu
 - Fixed MCP connection to localhost being routed through an active HTTP_PROXY/HTTPS_PROXY; NO_PROXY is now automatically extended with localhost and 127.0.0.1 when a proxy is configured
 - Fixed terminal scrollbar disappearing when Claude shows a choice/confirmation prompt (https://github.com/nbclaudecodegui/NetbeansClaudeCodeGui/issues/22)
diff --git a/pom.xml b/pom.xml
index 8d4a9c3a..2b676dee 100644
--- a/pom.xml
+++ b/pom.xml
@@ -6,7 +6,7 @@
 
     <groupId>io.github.nbclaudecodegui</groupId>
     <artifactId>netbeans-claude-code-gui</artifactId>
-    <version>0.21.48-SNAPSHOT</version>
+    <version>0.21.49-SNAPSHOT</version>
     <packaging>nbm</packaging>
     <name>Netbeans Claude Code GUI</name>
     <description>NetBeans plugin that provides a GUI for Claude Code CLI — run claude code sessions directly inside the IDE.</description>
diff --git a/src/main/java/io/github/nbclaudecodegui/ui/ClaudeSessionTab.java b/src/main/java/io/github/nbclaudecodegui/ui/ClaudeSessionTab.java
index 5e207e89..7b57bc56 100644
--- a/src/main/java/io/github/nbclaudecodegui/ui/ClaudeSessionTab.java
+++ b/src/main/java/io/github/nbclaudecodegui/ui/ClaudeSessionTab.java
@@ -697,11 +697,18 @@ private void showChatLayout(JediTermWidget widget) {
 
         southCardLayout = new CardLayout();
         southCard = new JPanel(southCardLayout) {
+            /**
+             * Returns (0, 0) so that JSplitPane can collapse the bottom panel
+             * freely when the tab is docked as a narrow side panel.
+             *
+             * Without this override, getMinimumSize() delegates to the visible
+             * child (e.g. promptPanel with a 3-row DecoratedTextArea + buttons),
+             * which reports a tall minimum height (~600 px). JSplitPane enforces
+             * that minimum, causing the divider to bounce back when the user tries
+             * to shrink the tab below that height (issue #19).
+             */
             @Override public java.awt.Dimension getMinimumSize() {
-                for (java.awt.Component c : getComponents()) {
-                    if (c.isVisible()) return c.getMinimumSize();
-                }
-                return super.getMinimumSize();
+                return new java.awt.Dimension(0, 0);
             }
             @Override public java.awt.Dimension getPreferredSize() {
                 for (java.awt.Component c : getComponents()) {
diff --git a/src/test/java/io/github/nbclaudecodegui/ui/ClaudeSessionTabMinSizeTest.java b/src/test/java/io/github/nbclaudecodegui/ui/ClaudeSessionTabMinSizeTest.java
new file mode 100644
index 00000000..d2637a10
--- /dev/null
+++ b/src/test/java/io/github/nbclaudecodegui/ui/ClaudeSessionTabMinSizeTest.java
@@ -0,0 +1,79 @@
+package io.github.nbclaudecodegui.ui;
+
+import java.awt.Dimension;
+import javax.swing.JSplitPane;
+import javax.swing.JPanel;
+import javax.swing.SwingUtilities;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.*;
+
+/**
+ * Regression test for issue #19: the session tab must be resizable below
+ * ~600 px when docked as a side panel.
+ *
+ * <p>Root cause: {@code southCard.getMinimumSize()} was delegating to the
+ * visible child component (e.g. promptPanel with a 3-row text area + buttons),
+ * which reported a tall minimum height. {@link JSplitPane} enforces the
+ * bottom component's minimum size, so the divider bounced back when the user
+ * tried to shrink the tab below that height.
+ *
+ * <p>Fix: {@code southCard.getMinimumSize()} now always returns (0, 0),
+ * letting JSplitPane collapse the bottom panel freely.
+ */
+class ClaudeSessionTabMinSizeTest {
+
+    /**
+     * Verifies that {@code southCard}'s minimum size is (0, 0) so that
+     * JSplitPane does not enforce a large lower bound on the tab height.
+     */
+    @Test
+    void southCardMinimumSizeIsZero() throws Exception {
+        SwingUtilities.invokeAndWait(() -> {
+            // Simulate the southCard construction from showChatLayout():
+            // an anonymous JPanel subclass with getMinimumSize() returning (0,0).
+            java.awt.CardLayout cardLayout = new java.awt.CardLayout();
+            JPanel southCard = new JPanel(cardLayout) {
+                @Override public Dimension getMinimumSize() {
+                    return new Dimension(0, 0);
+                }
+            };
+
+            // Add a child with a large preferred/minimum size (mirrors promptPanel).
+            JPanel tallChild = new JPanel() {
+                @Override public Dimension getMinimumSize()   { return new Dimension(400, 600); }
+                @Override public Dimension getPreferredSize() { return new Dimension(400, 600); }
+            };
+            southCard.add(tallChild, "prompt");
+            cardLayout.show(southCard, "prompt");
+
+            Dimension min = southCard.getMinimumSize();
+            assertEquals(0, min.width,
+                    "southCard minimum width must be 0 so JSplitPane can resize freely (issue #19)");
+            assertEquals(0, min.height,
+                    "southCard minimum height must be 0 so JSplitPane can resize freely (issue #19)");
+        });
+    }
+
+    /**
+     * Verifies that JSplitPane respects a (0,0) minimum on the bottom component
+     * and does not enforce the child's own large minimum size.
+     */
+    @Test
+    void splitPaneAllowsCollapseWhenMinSizeIsZero() throws Exception {
+        SwingUtilities.invokeAndWait(() -> {
+            JPanel bottomPanel = new JPanel() {
+                @Override public Dimension getMinimumSize() { return new Dimension(0, 0); }
+            };
+
+            JSplitPane splitPane = new JSplitPane(JSplitPane.VERTICAL_SPLIT,
+                    new JPanel(), bottomPanel);
+            splitPane.setResizeWeight(1.0);
+
+            // The minimum size of the split pane should allow it to be very small.
+            Dimension min = splitPane.getMinimumSize();
+            assertTrue(min.height < 100,
+                    "JSplitPane minimum height must be small when bottom component min size is (0,0) — " +
+                    "got " + min.height + " px; large value means resize is blocked (issue #19)");
+        });
+    }
+}