diff --git a/CHANGELOG.md b/CHANGELOG.md
index e20416b..9e27c03 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@
 * [UIPQB-162](https://folio-org.atlassian.net/browse/UIPQB-162) Errors when query includes a modified custom field.
 * [UIPQB-175](https://folio-org.atlassian.net/browse/UIPQB-175) Displays the "Smth went wrong" page, when the user clicks on "Select operator" dropdown and selects any of them, if there are deleted custom fields.
 * [UIPQB-164](https://folio-org.atlassian.net/browse/UIPQB-164) Columns are reset when user modifies query.
+* [UIPQB-179](https://folio-org.atlassian.net/browse/UIPQB-179) Fix string-based booleans improperly displaying.
 
 ## [1.2.7](https://github.com/folio-org/ui-plugin-query-builder/tree/v1.2.7) (2024-12-26)
 
diff --git a/src/QueryBuilder/ResultViewer/utils.js b/src/QueryBuilder/ResultViewer/utils.js
index 37be439..79863c3 100644
--- a/src/QueryBuilder/ResultViewer/utils.js
+++ b/src/QueryBuilder/ResultViewer/utils.js
@@ -11,16 +11,27 @@ export const formatValueByDataType = (value, dataType, intl, additionalParams =
 
   switch (dataType) {
     case DATA_TYPES.BooleanType:
-      return value
-        ? <FormattedMessage id="ui-plugin-query-builder.options.true" />
-        : <FormattedMessage id="ui-plugin-query-builder.options.false" />;
+      // booleans may be returned as true booleans, or strings 'true' or 'false'
+      if (typeof value === 'string') {
+        return value === 'true' ? (
+          <FormattedMessage id="ui-plugin-query-builder.options.true" />
+        ) : (
+          <FormattedMessage id="ui-plugin-query-builder.options.false" />
+        );
+      } else {
+        return value ? (
+          <FormattedMessage id="ui-plugin-query-builder.options.true" />
+        ) : (
+          <FormattedMessage id="ui-plugin-query-builder.options.false" />
+        );
+      }
 
     case DATA_TYPES.DateType:
       return <FormattedDate value={value} />;
 
     case DATA_TYPES.ArrayType:
       if (additionalParams?.isInstanceLanguages) {
-        return value.map(lang => formattedLanguageName(lang, intl)).join(' | ');
+        return value.map((lang) => formattedLanguageName(lang, intl)).join(' | ');
       }
 
       return value.join(' | ');
diff --git a/src/QueryBuilder/ResultViewer/utils.test.js b/src/QueryBuilder/ResultViewer/utils.test.js
new file mode 100644
index 0000000..dfaf2ac
--- /dev/null
+++ b/src/QueryBuilder/ResultViewer/utils.test.js
@@ -0,0 +1,39 @@
+import '@testing-library/jest-dom';
+import { render } from '@testing-library/react';
+import { IntlProvider } from 'react-intl';
+import { DATA_TYPES } from '../../constants/dataTypes';
+import { formatValueByDataType } from './utils';
+
+describe('formatValueByDataType returns correct value', () => {
+  test.each([
+    [undefined, DATA_TYPES.StringType, ''],
+    [null, DATA_TYPES.StringType, ''],
+
+    [true, DATA_TYPES.BooleanType, 'ui-plugin-query-builder.options.true'],
+    [false, DATA_TYPES.BooleanType, 'ui-plugin-query-builder.options.false'],
+    ['true', DATA_TYPES.BooleanType, 'ui-plugin-query-builder.options.true'],
+    ['false', DATA_TYPES.BooleanType, 'ui-plugin-query-builder.options.false'],
+
+    ['2024-01-01T12:30:00Z', DATA_TYPES.StringType, '2024-01-01T12:30:00Z'],
+    ['2024-01-01T12:30:00Z', DATA_TYPES.DateType, '1/1/2024'],
+    ['2024-01-01T12:30:00Z', DATA_TYPES.DateType, '1/1/2024'],
+
+    [[], DATA_TYPES.ArrayType, ''],
+    [['a'], DATA_TYPES.ArrayType, 'a'],
+    [['a', 'b', 'c'], DATA_TYPES.ArrayType, 'a | b | c'],
+
+    [1234, DATA_TYPES.IntegerType, '1234'],
+    [12.34, DATA_TYPES.NumberType, '12.34'],
+
+    [false, DATA_TYPES.StringType, ''],
+    ['foo', DATA_TYPES.StringType, 'foo'],
+  ])('value=%j of type=%p renders to %p', (value, type, expected) => {
+    const formatted = formatValueByDataType(value, type, null);
+
+    if (typeof formatted === 'string') {
+      expect(formatted).toBe(expected);
+    } else {
+      expect(render(<IntlProvider>{formatted}</IntlProvider>).container.innerHTML).toBe(expected);
+    }
+  });
+});